SRAM Apex Flat Top Chain - D1 Powerlock - 12 Speed - 118 LinksSRAM Apex D1 Flat Top Chain Introducing the Apex Flattop 12 Speed Chain for the 12 speed Apex drivetrains from SRAM. Flattop technology is so much more than a distinctive look. It allows SRAMs 12 speed chain to be lighter, stronger, and more durable than anything that came before. The Apex chain uses the same construction as the Rival and Force chains, with a polished grey finish. Flattop technology allows for a narrower chain with quieter operation