This Module is currently available.
Power Entry Panel with On/Off Switch and 1/4" Audio Output with Volume Control
This 3U 4HP power entry panel has a power jack, on/off switch with LED indicator, 1/8" jack input and 1/4" jack output with volume control. This panel is used to power the PBB-1 Eurorack Modular Synth Powered Bus Board.
https://www.mazzatron.com/product-page/eurorack-modular-synth-powered-bus-board