The item have 4 pcs, as same as picture, the 3pcs collet, and 1 pcs nut . collet 1/8" ,3.0mm 1/4" it is fit to Dewalt DW660S Type 1 Cut Out Tool,DW660S Type 2 Cut Out Tool,DW660S Type 3 Cut Out Tool,DW660 Type 1 Cut Out Tool,DW660 Type 2 Cut Out Tool,DC550A Type 1 18V Cordless Cut Out Tool,DC550W Type 1 Cut Out Tool,DC551 Type 1 Cut Out Tool,DW660SK Type 1 Cut Out Tool Kit,DW660SK Type 2 Cut Out Tool Kit,DW660SK Type 3 Cut Out Tool Kit,DC550P Type 1 18V Cut Out Tool,DC550K Type 1 18V Cut Out Tool,DC550KA Type 1 18V Cut Out Tool,DC550P (Type 1) Heavy Duty 18V Cordless Cut-Out Tool,DW660K (Type 1) Cut Out Tool Kit,DW660K (Type 3) Cut Out Tool Kit,DCS551B (Type 1) 20v Crdls Cutout Bar,DCS551B (Type 2) 20v Crdls Cutout Bar,DCS551D2 (Type 1) 20v Cordelss Cutout. Please Note: May not fit all specs of above models listed, please consult owner's manual for proper part number identification and proper installation it will be checked the size of collet before ordering, It is an authentic item that allows user to secure bits. Please note, this collet is for using bits with 1/8" ,3.0mm 1/4" arbors . It is made from durable metal and is sold individually. The collet nut that is used to secure this part is sold separately. You will need a wrench when replacing this collet.