P2020B1100CU 100-Amp 20-Space 20-Circuit Main Breaker Load Center Single phase 100 Amp main breaker load center with 20 spaces/20 circuits Features Siemens patented insta-wire technology which allows for quick and easy installation because screws are already backed out, ready for wire insertion on ground and neutral bars Copper bus All devices are provided with 2 factory installed ground bars Mounting tabs on the trim hold the load center in place freeing up both hands to drive the trim screws