BSS AC-V-BLK-US Analog Volume Controller for SoundWeb Systems (Black)The Soundweb Contrio AC V is a simple analog wall controller designed for use with BSS Audio Soundweb London devices. It is available in black or white, and in single gang US Decora or single gang EU form factor. It is designed to connect to General Purpose Inputs (GPI) (also known as "Control Inputs") found on Soundweb London devices. Most Soundweb London devices contain 12 GPI. The Soundweb London BLU GPX contains 36 GPI. The AC V contains a single