This high amperage SNAP ACTION, positive feel transbrake, nitrous or line lock button is the very popular RED "Over-sized, Mushroom" button. The Mushroom style cap measure 1-1/8" in diameter.
This is especially comfortable when wearing gloves or for "Pro-tree" racers who have to hit the trans brake button very quickly after staging, or for you bracket racers who "hit" the tree twice!
Comes complete with a stretch cord. Threaded shaft (which measures 5/8-24"), and locknut make it very simple to mount on a steering wheel, or any other desired location.
 
5/8 - 24" Threaded shaft