The Wolf Tooth 40t Cog for SRAM 10 Speed lets you modify your SRAM 10 speed cassette to be a wide range cassette that will shift smoothly and easily, matching the cassette's rotational orientation perfectly and thus unleashing your full potential as a climber.
It's compatible with SRAM PG-1030, 1050 and 1070 11-36t and 12-36t cassettes, as well as X0 11-36t (XG - 1080) cassettes, replacing the stock 17t and 14t cogs respectively. Thanks to extensive testing and precise machining by Wolf Tooth, you won't need any spacers but will be able to slot it right into your cassette.
This aluminium GC cog weighs 79g and is strong and rigid, so it will not only shift well but last for many a year. Best used in 1x setups, it can be run in a 2x drivetrain if paired with a long cage rear derailleur. If you're looking to increase your gear range by up to 11.2%, this upgrade is for you.