Features:1) Tapered connection: 6, 7, 12o 2) Threaded connection: R22, R25, R28, R32, R38, T38, T45, T51 3) Diameter: 30-127mm 4) Available types:a) "Retrac" button bitsb) Drop center button bitsc) Flat button bitsd) "Retrac" drop center button bitse) Reaming bitsPackaging: wood or plastic box package