SRAM RED E1 POWERMETER 1x 165x50 AERO DUB NoBB CARBONSram`s lightest, stiffest, and most accurate integrated power meter just got lighter with a new carbon crankarm construction Power readings are accurate within + 1. 5% and arent affected by climate conditions during a ride Ultra light hollow carbon fiber crankarms are 29 g lighter than previous generation Power meter is fully integrated into the chainring for lighter weight and greater accuracy Direct mount X SYNC chainring is aero and incredibly long