Check the listing for details. SRAM Force AXS Power Meter Spider - For Force 2x Threaded Mount X-Sync. Color: Black, Condition: New. Listed at 385.00 USD. When you need the best from your training data, the accuracy and reliability of the Force AXS Power Meter spider for thread mount 2x chainrings is the way to go. The spider design uses a proprietary thread-on chainring mount system which allows us to reduce weight and increase stiffness without compromising the ability to swap rings. This dual sided power measurement system, it’s accurate to +/-1.5% even as weather conditions change, and boasts unbeatable battery life.Thread Mount design is light, stiff and accurate, and fits Force 2x Thread Mount chainrings (Chainrings sold separately). Dual sided power measurement system, it’s accurate to +/-1.5% even as weather conditions change, and boasts unbeatable battery life (User replaceable CR2032 battery with 200-hour battery life). Bluetooth.