VIC FIRTH-American Custom Series. The American Custom line consists of a variety of models conceived and engineered by Vic Firth performer and teacher. The first manufacturer to apply the concept of a round striking surface to drumstick design, Vic developed the other originals that complete the line with jazz players in mind. An SD1 General with a hard, spun felt ball attached to the butt end. Ideal for fast changes on the cymbals. Felt ball size = 1 1/4 x 1"L = 16 5/8" = .635"