KAK 9MM AR15 CONFIGURABLE BUFFER KITKIT CONTAINS 1X 9MM EXTENDED STEEL BUFFER BODY4X ALUMINUM WEIGHTS4X STEEL WEIGHTS BLACK OXIDE COATED4X TUNGSTEN WEIGHTS4X RUBBER SPACER DISKS (1 SPARE)2X BUFFER BUMPERS (1 SPARE)2X ROLL PINS (1 SPARE)GREAT FOR 9MM FINICKY BUILDS, FULL AUTO, SPECIAL SUBSONIC WORK ETCINCLUDED SPARE PARTS-RUBBER SPACER DISK-DIFFERENT COLORED BUMPER (TO NOTATE CONFIGURATION)-ROLL PINKEEPS THE SYSTEM GOING FOR MANY WEIGHT SWAPSBUFFER COLORS MAY VARY, YOU WILL RECEIVE 2 DIFFERENT COLORS CONFIGURE AND TUNE YOUR BUFFER FOR YOU SPECIFIC NEEDSUSING DIFFERENT COMBINATIONS OF THE SUPPLIED PARTSWEIGHT COMBINATIONS UP TO 10 OZ ARE POSSIBLE