60gr no caps
64gr with flat caps or finger spin caps
65gr with spin-top caps
685 (Size D, 5mm x 11mm x 5mm),
concave, unshielded
RSO standard D pads
(19mm x 13mm x 1.15mm)
Polycarbonate body & caps
Aluminium hubs
Steel rings
Polyester strings

Changing the caps
The caps are interchangeable. You can press fit them on by hand and you need to remove them with air pressure. For this reason an air needle is provided with the yo-yo.

You will need to wind the tip of the needle with tape until it is thick enough to screw in the axle hole, creating an airtight seal. I find paper masking tape works best.
Below is a picture showing the air needle wound with purple paper masking tape:

Image showing the air needle wound with purple paper masking tape

You will also need a good modern bike pump or powerful air compressor that can generate roughly 12 BAR.

The caps will shoot out at a considerable force and with a loud bang so you must cover the yo-yo with damping material like a blanket and wear ear protection. You also need to make sure the direction the cap will shoot out at is not down. If you have the cap shooting down, the yo-yo will almost certainly get dinged by colliding with the cap.

!! Warning !! Do not hold the yo-yo half in your hand while blowing the caps out, especially not the spin top cap, because the force with which they eject is high and the caps on the Gemstones are sharp!!

Connect it to the pump or compressor, prepare for the bang and pump the air into it. If there are any air leaks between the pump and the yo-yo, there is a high chance you won’t be able to generate enough pressure. The finger spin caps especially need a lot of pressure to be removed.