YJYOYO has made some great innovations with 3D printed designs. These are replacement 3D Printed Hub Parts that fit their 3D Printed yoyos.

The hub parts serve as the bearing post in YJYOYO's 3D printed designs. The long hub part is used with a wide unresponsive bearing models (Atomicfire, SABER TRICK PRO) and the short with a narrow responsive bearing models(EASYTRICK, SABERTRICK, PARANOIA 3D).