Specification of Mouse Ball and Track Ball
Mouse Ball: Material I : Steel ball wrapped with High Grade Silicone Rubber. ( Heavy Ball )

Standard size: 25.4mm in diameter and 22 mm in diameter. Color : Grey.
Weight : For 25.4mm diameter : 49 gm +/- 1 gm.
For 22.0mm : 26; 28; 31 gm +/- 1 gm.

Material II : Neoprene Rubber ( NBR Light Ball )
Standard size: 22.0mm in diameter.; Color : Black.; Weight: 8/12 gm +/- 0.5 gm

Material III : Steel ball wrapped with Neoprene Rubber. ( NBR Heavy Ball )
Standard size: 20.3mm in diameter. ; Color : Black.; Weight: 19gm+/- 1gm.
Hardness: 70°, Shore A.
Temperature: 200℃

Track Ball : Material: Polyester. Standard size: 15.8mm in diameter; 25~ 60mm in diameter.
  Custom size is available upon request.
Color: Blue, Green or specified by Customer.
Hardness: 120°, Shore A.; Durability: 600,000 kilometer.

Mouse Ball construction:

Inner steel ball is around 3 ~ 4 mm
Smaller than the outer diameter
Depending on various models.

Application :

Heavy Ball : By the weight of metal ball, to create friction for moving the ball running, then pulling the light wheel for operating the IR couplers working.
Light Ball : Installation on top of keyboard, moving the ball by hand.

General Specification: Outside diameter tolerance : +/- 0.1mm
  Roundness : 0.05mm
Wear proof test : 0.0003mm/km
Appearance: No burrs is allowed. Color consistence.