brake lever for bicycle to control the throttle on straight drive while your 4wheeling So you can work the clutch and the brake. mount it on the shifter i saw it on here awhile back but can find it on here or Google
And typically you want to use a shifter, not a brake lever. The older Shimano ones work well because they don't have built in detents, so you can set them wherever is optimal for the situation.
On my old xj i had a bicycle click style shifter control mounted under dash. I used that to set a high idle and hold it when i need a certain rpm. But i also had a brake lever mounted on a jack handle between seats. Arm could lay comfortable on console and control throttle. And when i needed a little extra throttle for a short time i could control it with my hand while my feet worked the brake and clutch. Work very well.
I have the old shifter type and have wanted to go to the brake lever type for a while but then i got lazy and decided im going with an automatic instead. But they do come in handy.
Did the same thing jeepinmatt & others did with a shifter cable instead of a brake cable. Works like a champ during the stop-and-goes on the trails/hills!
Mine's mounted to my dash and its pivot point is actually a wing nut screw so you can adjust & then set it for holding the RPMs up for on board air or 'redneck cruise control'.