The SRAM RED AXS 12-speed Flattop Chain is designed with Flattop technology, enabling a narrower chain with quieter operation and increased strength and durability. It is compatible only with eTap AXS rear derailleurs and features hard chrome plated inner and outer plates that allow for faster and more precise shifts. The chain is constructed with HollowPin, providing increased strength and efficiency, and requires a Flattop Powerlock chain connector.