Completely functional and well taken care of ASRock B550M Steel Legend MicroATX Motherboard with socket AM4 and support for up to AMD Ryzen 5000 series processors. In great condition. Highlights are dual 2.5GbE LAN, onboard graphics, and 4 DIMM slots for up to 128GB of DDR4 RAM. I used this in a NAS and it is fantastic for such a use case, especially with an AM4 CPU and DDR4 RAM.
Comes in original box, but with no other hardware or accessories.
Full specs below:

• Unique FeatureASRock USB 3.2 Gen2
  - ASRock USB 3.2 Gen2 Type-A Port (10 Gb/s)
  - ASRock USB 3.2 Gen2 Type-C Port (10 Gb/s)
  ASRock Super Alloy
  - XXL Aluminum Alloy Heatsink
  - Premium 60A Power Choke
  - 50A Dr.MOS
  - Nichicon 12K Black Caps (100% Japan made high quality conductive polymer capacitors)
  - I/O Armor
  - Matte Black PCB
  - High Density Glass Fabric PCB
  - 2oz Copper PCB
  2.5G LAN
  ASRock Steel Slot Gen4
  ASRock Full Coverage M.2 Heatsink
  ASRock Hyper M.2 (PCIe Gen4x4)
  ASRock POST Status Checker (PSC)
  ASRock Full Spike Protection (for all USB, Audio, LAN Ports)
  ASRock Live Update & APP Shop
• CPU- Supports AMD AM4 Socket Ryzen™ 3000, 3000 G-Series, 4000 G-Series, 5000 and 5000 G-Series Desktop Processors*
  - Digi Power design
  - 10 Power Phase design
  
  *Please refer to CPU support list for details.
• Chipset- AMD B550
• Memory- Dual Channel DDR4 Memory Technology
  - 4 x DDR4 DIMM Slots
  - AMD Ryzen series CPUs (Vermeer) support DDR4 4533+(OC) / 4466(OC) / 4400(OC) / 4333(OC) / 4266(OC) / 4200(OC) / 4133(OC) / 4000(OC) / 3866(OC) / 3800(OC) / 3733(OC) / 3600(OC) / 3466(OC) / 3200 / 2933 / 2667 / 2400 / 2133 ECC & non-ECC, un-buffered memory*
  - AMD Ryzen series CPUs (Matisse) support DDR4 4533+(OC) / 4466(OC) / 4400(OC) / 4333(OC) / 4266(OC) / 4200(OC) / 4133(OC) / 4000(OC) / 3866(OC) / 3800(OC) / 3733(OC) / 3600(OC) / 3466(OC) / 3200 / 2933 / 2667 / 2400 / 2133 ECC & non-ECC, un-buffered memory*
  - AMD Ryzen series APUs (Cezanne) support DDR4 4733+(OC) / 4666(OC) / 4600(OC) / 4533(OC) / 4466(OC) / 4400(OC) / 4333(OC) / 4266(OC) / 4200(OC) / 4133(OC) / 4000(OC) / 3866(OC) / 3800(OC) / 3733(OC) / 3600(OC) / 3466(OC) / 3200 / 2933 / 2667 / 2400 / 2133 ECC & non-ECC, un-buffered memory*
  - AMD Ryzen series APUs (Renoir) support DDR4 4733+(OC) / 4666(OC) / 4600(OC) / 4533(OC) / 4466(OC) / 4400(OC) / 4333(OC) / 4266(OC) / 4200(OC) / 4133(OC) / 4000(OC) / 3866(OC) / 3800(OC) / 3733(OC) / 3600(OC) / 3466(OC) / 3200 / 2933 / 2667 / 2400 / 2133 ECC & non-ECC, un-buffered memory*
  - AMD Ryzen series APUs (Picasso) support DDR4 3333+(OC) / 3200(OC) / 2933 / 2667 / 2400 / 2133 non-ECC, un-buffered memory*
  - Max. capacity of system memory: 128GB**
  - Supports Extreme Memory Profile (XMP) memory modules
  - 15μ Gold Contact in DIMM Slots
  
  *For Ryzen Series APUs (Picasso, Cezanne and Renoir), ECC is only supported with PRO CPUs.
  Please refer to below table for AMD non-XMP memory frequency support. For more details, please refer to the QVL on ASRock's website.
  
  Ryzen Series CPUs (Vermeer):
  
  
  Ryzen Series CPUs (Matisse):
  
  
  Ryzen Series APUs (Cezanne):
  
  
  Ryzen Series APUs:
  
  
  Ryzen Series CPUs (Picasso):
  
  
  SR: Single rank DIMM, 1Rx4 or 1Rx8 on DIMM module label x=1 or 2
  DR: Dual rank DIMM, 2Rx4 or 2Rx8 on DIMM module label
  
  **Due to the operating system limitation, the actual memory size may be less than 4GB for the reservation for system usage under Windows® 32-bit OS. For Windows® 64-bit OS with 64-bit CPU, there is no such limitation.
• BIOS- 256Mb AMI UEFI Legal BIOS with GUI support
  - Supports "Plug and Play"
  - ACPI 5.1 compliance wake up events
  - Supports jumperfree
  - SMBIOS 2.3 support
  - CPU, CPU VDDCR_SOC, DRAM, VPPM, 1.05V_PROM_S5, 2.5V_PROM, +1.8VSB, VDDP Voltage Multi-adjustment
• Graphics- Integrated AMD Radeon Vega Series Graphics in Ryzen Series APU*
  - DirectX 12, Pixel Shader 5.0
  - Shared memory default 2GB. Max Shared memory supports up to 16GB.**
  - Dual graphics output: support HDMI and DisplayPort 1.4 ports by independent display controllers
  - Supports HDMI 2.1 with max. resolution up to 4K x 2K (4096x2160) @ 60Hz
  - Supports DisplayPort 1.4 with max. resolution up to 5K (5120x2880)@120Hz
  - Supports Auto Lip Sync, Deep Color (12bpc), xvYCC and HBR (High Bit Rate Audio) with HDMI 2.1 Port (Compliant HDMI monitor is required)
  - Supports HDR (High Dynamic Range) with HDMI 2.1
  - Supports HDCP 2.3 with HDMI 2.1 and DisplayPort 1.4 Ports***
  - Supports 4K Ultra HD (UHD) playback with HDMI 2.1 and DisplayPort 1.4 Ports
  - Supports Microsoft PlayReady
  
  *Actual support may vary by CPU
  
  **The Max shared memory 16GB requires 32GB system memory installed.
  
  ***Picasso supports HDCP 2.2 with HDMI 2.0 Port
• Audio- 7.1 CH HD Audio with Content Protection (Realtek ALC1220/ALC1200 Audio Codec)
  - Premium Blu-ray Audio support
  - Supports Surge Protection
  - PCB Isolate Shielding
  - Individual PCB Layers for R/L Audio Channel
  - Gold Audio Jacks
  - Nahimic Audio
• LAN- 2.5 Gigabit LAN 10/100/1000/2500 Mb/s
  - Dragon RTL8125BG
  - Supports Dragon 2.5G LAN Software
  - Smart Auto Adjust Bandwidth Control
  - Visual User Friendly UI
  - Visual Network Usage Statistics
  - Optimized Default Setting for Game, Browser, and Streaming Modes
  - User Customized Priority Control
  - Supports Wake-On-LAN
  - Supports Lightning/ESD Protection
  - Supports Energy Efficient Ethernet 802.3az
  - Supports PXE
• SlotsAMD Ryzen series CPUs (Vermeer and Matisse)
  - 2 x PCI Express x16 Slots (PCIE1: Gen4x16 mode; PCIE3: Gen3 x4 mode)*
  AMD Ryzen series APUs (Cezanne and Renoir)
  - 2 x PCI Express x16 Slots (PCIE1: Gen3x16 mode; PCIE3: Gen3 x4 mode)*
  AMD Ryzen series APUs (Picasso)
  - 2 x PCI Express x16 Slots (PCIE1: Gen3x8 mode; PCIE3: Gen3 x4 mode)*
  
  - 1 x PCI Express 3.0 x1 Slot
  - Supports AMD Quad CrossFireX™ and CrossFireX™
  - 15μ Gold Contact in VGA PCIe Slot (PCIE1)
  - 1 x M.2 Socket (Key E), supports type 2230 WiFi/BT PCIe WiFi module
  
  *Supports NVMe SSD as boot disks
• Storage- 6 x SATA3 6.0 Gb/s Connectors, support RAID (RAID 0, RAID 1 and RAID 10), NCQ, AHCI and Hot Plug*
  - 1 x Hyper M.2 Socket (M2_1), supports M Key type 2280 M.2 PCI Express module up to Gen4x4 (64 Gb/s) (with Vermeer, Matisse) or Gen3x4 (32 Gb/s) (with Cezanne, Renoir and Picasso)**
  - 1 x M.2 Socket (M2_2), supports M Key type 2280 M.2 SATA3 6.0 Gb/s module and M.2 PCI Express module up to Gen3 x2 (16 Gb/s)**
  
  *M2_2 and SATA3_5_6 share lanes. If either one of them is in use, the other one will be disabled.
  
  **Supports NVMe SSD as boot disks
  NVMe SSD is not supported with AMD Athlon™ 3000G Processors
• Connector- 1 x SPI TPM Header
  - 1 x Power LED and Speaker Header
  - 2 x RGB LED Headers*
  - 2 x Addressable LED Headers**
  - 1 x CPU Fan Connector (4-pin)***
  - 1 x CPU/Water Pump Fan Connector (4-pin) (Smart Fan Speed Control)****
  - 4 x Chassis/Water Pump Fan Connectors (4-pin) (Smart Fan Speed Control)*****
  - 1 x 24 pin ATX Power Connector (Hi-Density Power Connector)
  - 1 x 8 pin 12V Power Connector (Hi-Density Power Connector)
  - 1 x 4 pin 12V Power Connector (Hi-Density Power Connector)
  - 1 x Front Panel Audio Connector
  - 2 x USB 2.0 Headers (Support 4 USB 2.0 ports) (Supports ESD Protection)
  - 2 x USB 3.2 Gen1 Headers (Support 4 USB 3.2 Gen1 ports) (Supports ESD Protection)
  
  *Support in total up to 12V/3A, 36W LED Strip
  
  **Support in total up to 5V/3A, 15W LED Strip
  
  ***The CPU Fan Connector supports the CPU fan of maximum 1A (12W) fan power.
  
  ****The CPU/Water Pump Fan supports the water cooler fan of maximum 2A (24W) fan power.
  
  *****The Chassis/Water Pump Fan supports the water cooler fan of maximum 2A (24W) fan power.
  CPU_FAN2/WP, CHA_FAN1/WP, CHA_FAN2/WP, CHA_FAN3/WP and CHA_FAN4/WP can auto detect if 3-pin or 4-pin fan is in use.
• Rear Panel I/O- 2 x Antenna Mounting Points
  - 1 x PS/2 Mouse/Keyboard Port
  - 1 x HDMI Port
  - 1 x DisplayPort 1.4
  - 1 x Optical SPDIF Out Port
  - 1 x USB 3.2 Gen2 Type-A Port (10 Gb/s) (Supports ESD Protection)
  - 1 x USB 3.2 Gen2 Type-C Port (10 Gb/s) (Supports ESD Protection)
  - 4 x USB 3.2 Gen1 Ports (ASMedia ASM1074 hub) (Supports ESD Protection)
  - 2 x USB 2.0 Ports (Supports ESD Protection)
  - 1 x RJ-45 LAN Port with LED (ACT/LINK LED and SPEED LED)
  - 1 x Clear CMOS Button
  - HD Audio Jacks: Rear Speaker / Central / Bass / Line in / Front Speaker / Microphone (Gold Audio Jacks)
• Software and UEFISoftware
  - ASRock Motherboard Utility (A-Tuning)
  - ASRock Polychrome SYNC*
  UEFI
  - ASRock Full HD UEFI
  - ASRock Instant Flash
  
  *These utilities can be downloaded from ASRock Live Update & APP Shop.
• Accessories- 2 x SATA Data Cables
  - 2 x Screws for M.2 Sockets
• Hardware Monitor- Temperature Sensing: CPU, CPU/Water Pump, Chassis/Water Pump Fans
  - Fan Tachometer: CPU, CPU/Water Pump, Chassis/Water Pump Fans
  - Quiet Fan (Auto adjust chassis fan speed by CPU temperature): CPU, CPU/Water Pump, Chassis/Water Pump Fans
  - Fan Multi-Speed Control: CPU, CPU/Water Pump, Chassis/Water Pump Fans
  - Voltage monitoring: +12V, +5V, +3.3V, CPU Vcore, CPU VDDCR_SOC, DRAM, VPPM, 1.05V_PROM_S5, +1.8V, VDDP
• Form Factor- Micro ATX Form Factor: 9.6-in x 9.6-in, 24.4 cm x 24.4 cm
  - 2oz Copper PCB
• OS- Microsoft Windows® 10 64-bit / 11 64-bit
• Certifications- FCC, CE
  - ErP/EuP ready (ErP/EuP ready power supply is required)