Due to panel space limitations on the PM MKII, it was not possible to add a bunch of aux returns. So there is this extension that gives you the choice of just adding returns on this expander, or using the PM Channels MKII to add returns to a channel. 

Features:

• 3x Stereo Aux Returns
• PM MKII Connectivity
• No Power (Passive)
• Toggle for Pre/Post Master Insert Routing
• 2nd panel for Upside-down Mounting