UL and CSA heavy-duty S fuses are for use in air conditioners, furnace blower motors, swimming pool pumps, deep freezers or where motors frequently turn on and off. The S rejection base plug fuse is an industrial strength product and provides superior protection that will resist nuisance openings under repeated motor startups. Available in a wide ampere range to permit exact sizing to motor load. Rejection base for critical circuit protection such as air conditioners, furnace blowers, swimming pool pumps, deep freezers or any circuit where motors turn on and off frequentlyHeavy-duty S fuses are for use in air conditioners, furnace blower motors, swimming pool pumps, deep freezers or where motors frequently turn on and off. The S rejection base plug fuse is an industrial strength product and provides superior protectioExtra-large clear window makes it easy to see if fuse is blownTamper-proof basePorcelain threads prevent a larger amp fuse from being usedHeavy duty125 volt maximum20 amp2 count