Adjust compatible heated socks without reaching for the batteries. This four-button replacement remote selects high, medium or low heat for supported Powersheer Micro wireless sock batteries and Standard Insoles . It works with battery model MW37V122 and the MWCB37V42221 battery set; it does not work with MW37V040 Costco sock batteries. Compatible: Merino Heated Socks batteries 3.7V Powersheer® Wireless Sock Batteries MWCB37V42221 (Clamshell part number) MW37V122 (Part number on individual battery) Standard Insoles Not compatible with MW37V040 batteries as seen at Costco. The part number for those remotes are MWRA4BTN2023.