Attenuator-Inverter Module from Electronic things... and stuff on Tindie
Tripp Lite Remote Control Module Inverters and Inverter / Chargers - power control unit - APSRM4 - Power Management - CDW.com
Amazon.com: 1000W Power Inverter, Mutipurpose Power Step Up Inverter Module Inverter Board Practical DIY Metal and PCB Inverter Module, for Camping Car Home Lamps Soldering and so on(DC 24V) : Automotive
Amazon.com: Electronic Inverter Module, Power Converter Board Front Stage No Protection DC12V/24V Input for Emergency Power Supplies : Automotive
Amazon.com: Electronic Inverter Module, Power Converter Board Front Stage No Protection DC12V/24V Input for Emergency Power Supplies : Automotive