Manufacturer Happ Controls, Inc. Availability Happ Controls 3" Trackball Mounting Kit (NOS) Happ Part #55-1102-00 $20.00 Qty: Add to cart Email a friend Question about product? Add to wishlist Details Original, never used, Happ Controls 3" Trackball Mounting Kit Clear Zinc with hardware. Item is new old stock, original Happ Part # 55-1102-00. Used to mount a 3" trackball on a control panel.