Super pro at the monster mopar was 1/4 mile and big dog was 1/8 mile. they were both box classes but you could choose, if you wanted to run 1/8th you entered big dog if you wanted to run 1/4 you entered super pro. Luckily i have a dragster that is set up to run both, a door car that is set up for the 1/8 and another door car set up for the quarter. I dont recomend this LOL its hard on the wallet and your sanity