It's the signal-switching side of a motor starter or contactor assembly: the 4 NO contacts handle control logic, PLC inputs, or pilot-duty loads up to 10 A at 24 V, derating to 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. The 10 A thermal current rating tells you the contact block can carry that continuously in free air; the voltage-specific ratings govern the interrupting capacity at each level.
Width of 45 mm, depth of 72 mm, height of 57.5 mm — this is the standard S00 block that clips onto a 35 mm DIN rail or screws directly to a mounting plate. The screw terminals accept 2x 0.5…1.5 mm², 2x 0.75…2.5 mm², or 2x 4 mm² solid conductors — typical for control wiring up to 12 AWG.
Contact reliability and electrical endurance
Rated for one incorrect switching operation per 100 million cycles at 17 V, 1 mA — that's the dry-circuit reliability figure. For a 4 NO block used in PLC or safety-circuit feedback, that means you can trust the contacts to close on low-energy signals without oxide-film issues.