Replacement 110-20 snap disc for Quadra-Fire and Heatilator Eco Choice pellet and wood stoves. Also, this part is known as a thermodisc or snap switch. Fits the following HHT stove models: Quadrafire Pellet Stoves: Santa Fe (Snap disc #1) Santa Fe Insert (Snap disc #1) Castile (Snap disc #1) Castile Insert (Snap disc #1) Quadrafire Woodstoves: 4100-I ACT Bodega Bay Heatilator Eco-Choice Pellet Stoves: PS35 PS50 CAB50 Quadra-Fire part # SRV230-1220 OEM Quadrafire part.