All-new design with removable and replaceable thread-mount chainrings, available in 38T-46T Power readings are accurate within +/-1.5% and aren’t affected by climate conditions during a ride User replaceable CR2032 battery with 200-hour battery life Measures right and left leg power balance Ultra-light hollow carbon fiber crankarms are 29 grams lighter than previous generation DUB bottom bracket adds durability and simplicity Waterproof (IPX7 waterproof to 1 meter for 30 minutes) SRAM Model ID: FC-RED-1WP-E1