The Duncan MOD Spacer kit 5158PK included a long axle screw, two metal bearing spacers, and two plastic MOD Spacers. The MOD Spacers used their molded-in 4-hole response system instead of silicone response pads. Because this kit does not come with a bearing like the Duncan MOD Spacer kit model 5158PK, you must use the bearing that already comes with your yo-yo.
The kit let you change the shape and responsiveness of your Duncan off-string yo-yo (or any other compatible off-string yo-yo from another maker).
