100A Round Meter Base 1)Material: metal or copper 2)Size:1/2", 3/4", 1",5/4" available 3)1phase,100A,4jaw ... Fix hub sizeSM-100-B1 Phase,100A,120/240Vac,4 jaw 1/2"SM-100-C1 Phase,100A,120/240Vac,4 jaw 3 ... /4"SM-100-D1 Phase,100A,120/240Vac ... ,4 jaw 1"SM-100-E1 Phase,100A,120/240Vac,4 jaw 1-1/4" 100A Round ...