As professional coaches know, compared to simply measuring heart rate, which can easily be affected by environmental factors or personal physiological conditions, using a power meter is the best way to gain metrics for training because the data given by direct force shows the real output from every pedal stroke.Features:- IPX7 waterproof, anti-dust casing with a closed magnetic rechargeable design protects the Power Pro from water or dust while riding- 107mm BCD for SRAM Force and Rival 4 bolt 1x or 2x chain rings- High-capacity lithium battery delivers up to 150 hours of riding on a single charge- Built-in magnetic connector makes recharging easy- LED Indicators display connection and battery statusSpecifications:- Weight: 155g (spider only)- Size: 125*125*200mm / 4.9*4.9*7.8 inch (L*W*H mm)- Waterproof: IPX7- Bolt Pattern: 4 Bolt- Bolt Circle Diameter (BCD): 107mm- Chain Ring Compatibility: 1x ,2x- Connections: BLE/ANT+- Battery Type: Lithium-ion- Battery Run Time: 100 Hours- Battery Charge Time: 1 hr- Battery Life Indicator: Yes- Accuracy: ± 1.5%- Temperature Compensation: Yes- Left/Right Balance: Yes- Firmware: Giant Ride link