WRX Heat Strips Fit the following: Rheem - RH1, RH2, RHL, RHS, RHP. Ruud - UHLA, UHSA, UHLL, UHSL, UHKL, UHKA, UHPLStandard Features: - Elements protected by metal wrapper - Point Suspension element support system which eliminates hot spots to extend heater life - Time delay between steps which recycles on power interruption or brown-out - No off delay (a problem with sequencers) to increase SEER rating and prevents heating overshoot - Chatter and Rapid-cycle Resistant Contactors rated for 250,000 cycles - Rounded metal corners for safe handling. - Modular control plug for installation ease - ETL certified