LS Electric offers miniature circuit breakers in both UL1077 and UL489. UL1077 miniature circuit breakers (BK63H) are suitable for supplemental overload and short circuit protection while UL489 miniature circuit breakers (BK63HU) are used for branch circuit protection. The BK63H series (UL1077) and the BK63HU series (UL489) are both available in 1, 2, 3 or 4 poles, in B, C or D trip curves and from 1 to 63 amp.