The Siemens 3RB1016-1SB0 is a solid-state overload relay rated 3.0...12 A, class 10 trip curve, designed for direct mounting onto a contactor in size S00. Screw terminals, manual-automatic reset.
Size S00 frame — mounts directly onto the matching contactor, saving DIN-rail space in the panel. Screw connection, so no special tooling needed for the wire terminations. Manual-automatic reset gives the panel builder flexibility: automatic for remote restart, manual for troubleshooting.