The cartridge works as a pressure balance valve to protect you from sudden temperature changes in the water supply, ensuring a comfortable shower experience. It is specifically compatible with Gerber’s Hardwater II and SafeTemp II faucets, including models like GS-103 and GS-105. This specific cartridge is also known by alternative part numbers, including 95-152, 0095152, and 158166. It is often replaced in conjunction with the 95-154 mixing control cartridge.