A solid-state relay (SSR) is an electronic switching device that switches on or off when an external voltage (AC or DC) is applied across its control terminals . It serves the same function as an electromechanical relay, but has no moving parts and therefore results in a longer operational lifetime. https://youtu.be/fxRk0coqkV0 Features: Dual-channel DC AC dual-channel control, with heavy-duty screws. The relay has brass contacts for good contact that has excellent conductivity. The fire-resistant housing is resistant to moisture, shock, and corrosion. With a thick, durable, and long-life heat sink base. High brightness with red and green indicators, easy to operate. Specifications: Model: SSR1K1B40DA Nominal AC current: 10A / 25A / 40A /60A /80A AC voltage : 24-600VAC. Control voltage: 3-32VDC. Control current: ≤ 20 mA. Control method: AC controlled by DC Type: Dual AC DC control Indicator : red + green. Product size: approx. 2,283 x 1,732 x 1102 in. Package Includes: 1 x Tense Solid State Relay 3-32VDC SSR-1K1B40DA