The CMRD2455 from Crydom is single pole single throw SPST (1 Form A) solid state relay with integrated heat sink, NO contact configuration and screw terminal. This relay has AC, zero cross output and 55A, 24 to 280V load ratings. Operates at input voltage range from 3 to 32VDC. Dimensions of this relay with heat sink are: 3.0" (76.2mm) x 1.75" (44.5mm) x 4.3" (109.2mm).