HOLE PUNCH KEYED 30.5MM DIAMETER FOR DMR20 AC/DC VOLTAGE METERS; Punch Size:30.5mm; Product Range:NANOMETER Series; Features:4 Keying Notches; For Use With:MuRata DMR20-1-ACV-R-C AC & DMR20-10-DCM-R-C DC Volt Meters ;RoHS Compliant: No