This product is part of the patented quick-lock technology and is used with either the adjustable dumbbells or adjustable kettlebells for securely holding weight in place.

Dumbbell use: This longer locking screw is the same part used with the 120 Add on Kit. If you have the 75 lb set and want to just make one heavier dumbbell you can use two of these Add on Screws and load on more plates from the other dumbbell.

Kettlebell use: You can use this locking screw with the 5 lb and 2.5 lb plates from the standard Quick-Lock Dumbbell system to get up to the 80 lbs max size Kettlebell. The larger 22.5 lb weight plate is not required.