With no moving parts, this water-sensing switch will never jam on debris.Attwood's S3 electronic bilge switch is the industry answer to broken mechanical switches, jammed float mechanisms and ever annoying excessively cycling pump. The S3 Series bilge pump switch incorporates a proprietary Solid State electronic Sensing Technology to detect bilge water levels and trigger pump activation more consistently, more reliably and for a significantly longer working life compared to traditional mechanical float switches.Key FeaturesCannot jam on debrisFive-year warrantySpecifications Voltage: 12V DC Dimensions: 3 3/16"H x 1 5/8"W x 2 11/16"HAmperage capacity: 15AManufacturer's Documentation Brochure Technical Specifications Installation Instructions