The Logitech Z313 Replacement Subwoofer is a Grade B tested product designed for Logitech Z313 portable speaker systems. This black cube-shaped subwoofer delivers 50W RMS power and features surround sound formats of 2.1. It is equipped with audio inputs of 3.5mm and connectivity options like a headphone jack, wired connection, audio jack, and RCA jack. Additionally, it includes features such as volume control, headphone jack, and AC power for enhanced audio experience. The Logitech Z313 Replacement Subwoofer is a reliable option for those looking to replace or upgrade their current speaker system.