SYR-100A series round meter base 100Amps,120~240VAC, Single phase,4 terminal,2 ... hub size:1/2",3/4",1" SYR-100A Series Round meter box description: Item Code No.No. of terminalscircuit of ... applicationapplicable meter form designationMeter class ratingFix hub sizestds packspacking sizeSYR-100A4 2W ... sealing ringFix hub size:1/2,3/4,1, meter socket