The Rectorseal RSH-50 is a single phase 120/240 VAC type 1 surge protector. The small physical size makes it an ideal accessory for A/C units, heat pumps, mini split units, and furnaces to protect the electronic components against power surges. It is weather-rated under NEMA 4X, utilizes long-lasting gas discharge tube technology and features a green LED to easily indicate protection is active. Protects up to 50,000-amp single surges and up to 10,000-amp repetitive surges. UL listed.