Optimize your power transfer with the Box One Oversized Single Speed Cog, engineered for elite-level performance and durability. CNC-machined from high-strength chromoly steel, this cog features a sleek ED black finish with laser-etched graphics for a premium look that lasts. Designed specifically for OS spline drivers—including the Onyx Ultra SS Driver—it’s compatible with both 3/32” and 1/8” chains, giving you flexibility across race setups. Stealth Pro hub