- Quarq Dzero XX1 Boost power meter spider must be paired with a XX1 Eagle DUB 8-bolt crankset and a 104 BCD X-SYNC 2 chainring \n - Not compatible with SRAM's 3-bolt direct mount interface \n - Bluetooth low energy technology and ANT+ wireless data transfer \n - MagicZero technology automatically checks and recalibrates your power meter as you ride, no need to manually calibrate \n - AxCad system provides no-magnet cadence data