ROLLMASTER STEEL BEARINGS - Roller-type bearing provides the ultimate smoothness and friction-free ball operation. 

INTERCHANGEABLE BEARINGS - Choose between Ruby or ROLLMASTER ball bearings.  Replacement parts are sold separately.

ERGONOMIC DESIGN - Supports your hand in a natural angled position 28 degrees for all-day comfort.

OVERSIZED SILVER BALL - The large 36mm ball enables precise movements from one end to the other even on large screens.

DIMENSIONS - Width 3.8 inch x Length 5.0 inch x Height 2.0 inch, Weight : 5.2oz