It's the replaceable coil for SIRIUS contactors in that voltage class, so if you're on-site with a burned-out coil on a 24 VAC contactor and the line's down, this is the part that gets you back up without swapping the whole contactor block.
Screw terminals — standard for panel builders who prefer a positive clamp over spring-cage. The coil is designed for SIRUS contactors in the same frame size; it mounts directly on the contactor yoke. No special tools beyond a screwdriver. AC 24 V at 50/60 Hz means it works on either frequency without derating the pull-in voltage.
