Basically any Innova driver is going to be a small diameter discs. A Roc, Cobra, Stingray, Viper, Buzzz, Coyote, Mako, Shark, Wolf...all of those are larger 21.7 cm discs. If you have any of those you can compare.ehh what if i dont have either of them...lol i dont throw cheetahs or rocs.. ill just grab the ruler