Comparison : Item # B3540-52500BA1W, Aluminum Liquid Level Gage with Card Thermometer and Shut-off, 25” Centerline, Front Mount 1/2"-20
Item # B3540-52500BB1W, Aluminum Liquid Level Gage with Card Thermometer and Shut-off, 25” Centerline, Back Mount 1/2"-20 with Nuts
Item # B3540-52500BN1W, Aluminum Liquid Level Gage with Card Thermometer and Shut-off, 25” Centerline, 1/4" Male NPT Adapters
Item # B3540-52500BN2W, Aluminum Liquid Level Gage with Card Thermometer and Shut-off, 25” Centerline, 3/8" Male NPT Adapters
Item # B3540-52500BN3W, Aluminum Liquid Level Gage with Card Thermometer and Shut-off, 25” Centerline, 1/2" Male NPT Adapters