The SRAM Red AXS E1 Power Meter Spider for Threaded Mount is engineered for top-tier accuracy and reliability in your training data. Its proprietary Thread Mount system reduces weight, boosts stiffness, and allows for easy chainring swaps (available in 38T-46T). With dual-sided power measurement and accuracy to within 1.5 percent, even in changing weather, this power meter is designed for precision. Featuring a 200-hour battery life from a user-replaceable CR2032, it includes Bluetooth and ANT+ connectivity, MagicZero auto-calibration, and IPX7 waterproofing. The SRAM Red AXS E1 Power Meter is a great addition to your crankset to help improve speed and consistency on the bike.