An engineering marvel, and a pain in the @##. We installed a 4:1 Klune "Goliath" to our rock crawler pinz. The reduction was impressive. The only issues we ran into was an ugly vibration due to the shortness of the shaft between transmission and underdrive. One of these days we will fab a CV shaft for this location and we should be good to go. There were 5 prototypes built....it's not likely we will build anymore.