The Beverage-Air 504-539B drain tube heater is a replacement part that is rated for 115V and is suitable for use with compatible Beverage-Air refrigeration equipment to prevent frost buildup in the drain tube. The drain tube heater fits Beverage-Air models CRG24, HF1-1S, HF1-1SONIC, HF2, HF2-1S, HF3-5S, KF12, KF24, KF36, KF48, KF74, and PRF12-12. This replacement part is approved by the original equipment manufacturer (OEM).