Sram Force Flattop E1 12-13s 126 Links Chain

PowerLock
SRAM chain engineers developed PowerLock as the safe and consistent way to connect SRAM chains without Luse of tools. While the PowerLock requires no special tools for assembly, given the narrow tolerance range of a 10, 11 and 12 speed chain, each PowerLock should only be used once.

Flattop
Flattop technology allows for a narrower, lighter chain and allows for quieter operation, as well as greater strength and durability.

Lock: quick release fastener