The Sram Red OG (OpenGlide) is the key to smooth performance in competition and on the open road. To take full advantage of the power and promise of the Sram Rival 10 speed groupset, you need a cassette and chain that are up to the task. With the Sram Red OG Cassette's semi-spidered design, Sram have removed specific sections of material from the small cogs, creating a cogset that shifts efficiently and positively in all situations.   OpenGlide technology allows for the smoother transition between gears when up and downshifting. Semi-spidered design is light, strong and efficient.    Features Lightweight: Innovative CNC‘d chromoly steel construction. Durable: 35% harder than titanium!. Stiff: 15% stronger than its competitor. OpenGlide technology allows for smoother transition between gears. Weight: 155g.   Specification Speed: 10. Sprockets on Spider: 3. Lock Ring Material: Forged 7000 series alloy. Sprocket Material: Heat-treated steel. Cassette Weight: 210g. Recommended Chain: PC-1090R, PC-1090, PC-1070.