... size:1/2",3/4",1"1-1/4 MT-100R Series Round meter box description: Item Code No.No. ... applicationapplicable meter form designationMeter class ratingFix hub sizestds packspacking sizeMT-100R-B4 2W/3W,1Phase 1S/2S 100 1/2" 40 ... 74X38X42CMMT-100R-C4 2W/3W,1Phase 1S/2S 100 3/4" 40 ... 74X38X42CMMT-100R-D4 2W/3W,1Phase 1S/2S 100 1" 40 74X38X42CMMT ...