Jain 1/2 in. Socket x 3/4 in. Spigot Power-Loc Adapter — OrchardValleySupply.com
Light & Motion 1/2" to 3/4" Loc-Line Adapter 800-0203-A B&H
Irritec Perma-Loc Tape x MPT Adapter-Perma-Loc Size:1"-Thread Size:3/4" | eBay
Ops-Core Wing-Loc Rail Adapter. Durable and lightweight
VCA 25mm-30mm Pipe to 3/4in Loc-Line Flex-Series Adapter
Amazon.com: Scosche LOC2SL Line Output Converter Adjustable Amplifier Add On Module for Car Stereo, 2-Channel Signal Sensing Speaker Wire to RCA Adapter with Remote Control Knob, Black : Electronics