3RU2136-4HB0 Siemens  thermal overload relay for mounting on Sirius 3RT203 size S2 contactors. and is adjustable from 40A-50A. This Class 10 overload (trips in 10 seconds or less) has phase loss protection, manual or automatic reset and two auxiliary contacts, one normally open and one normally closed. If you are looking for a lower AMP range than the 3RU2136-4HB0 offers, you can use the 3RU2136-4GB0 or for a higher AMP range the 3RU2136-4QB0 adjusts up to 57 AMPS.