The Thunderball is the name Cimarron gave to the Pietta version of their Thunderer. Thunderball grips are shaped like the Uberti Thunderer but are a tad thinner (not nearly as thin as the Lightning, though). So, the gun you are looking at at one time had the Thunderball-type grip but has been changed for plow handle. That essentially makes it the same as an EMF GW-II or a Cimarron Frontier.