Overall Dimensions: 3 ¾”W x 3 ¾”H Faceplate Dimensions: 3 ½”W x 3 ½”H Bolt hole spacing: 2 15/16”W x 2” H (hole center to hole center) K101 “pigtail” wiring harness included 12V DC Color: White or Black Easy readout Monitor tank levels Monitor battery level Control for water pump Controls for electric and gas water heaters