OUTSIDE MICROMETERS with Extension Anvil Collars Features: • Ratchet and lock nut. • Extension collars:25mm/1", 50mm/2" (within 1000mm/40") 50mm/2",100mm/4"(over 1000mm/40") • Carbide tipped. • Pipe combined frame for light weight and high rigid. • Resolution:0.01mm,0.0001" inch.• Counter readout:0.01m,0.001" inchInch Metric RangeGraduationModel No.RangeGraduationModel No.12-16"0.001"600-9901300-400mm0.01mm600-980116-20"0.001"600-9902400-500mm0.01mm600-980220-24"0.001"600-9903500-600mm0.01mm600-980324-28"0.001"600-9904600-700mm0.01mm600-980428-32"0.001"600-9905700-800mm0.01mm600-980532-36"0.001"600-9906800-900mm0.01mm600-980636-40"0.001"600-9907900-1000mm0.01mm600-980740-48"0.001"600-93081000-1200mm0.01mm600-900848-56"0.001"600-93091200-1400mm0.01mm600-900956-64"0.001"600-93101400-1600mm0.01mm600-901064-72"0.001"600-93111600-1800mm0.01mm600-901172-80"0.001"600-93121800-2000mm0.01mm600-901280-88"0.001"600-93132000-2200mm0.01mm600-901388-96"0.001"600-93142200-2400mm0.01mm600-901496-104"0.001"600-93152400-2600mm0.01mm600-9015104-112"0.001"600-93162600-2800mm0.01mm600-9016112-120"0.001"600-93172800-3000mm0.01mm600-9017