The Rubin 12 High Speed Disc has two rows of symmetrically arranged 29" discs that minimize side draft while mixing trash into 8" of soil. The Rubin 12 does not rely on weight to penetrate the soil. Instead it uses unique disc angle and forward angle to pull the discs into the soil. Ideal speed is 8-10 mph. It requires approximately 20 HP/ft and comes in models up to 31'.