You need a ANT+ /BLE Speed cadence sensor. Recommend JetBlack Speed/Cadence or Garmin Speed/Cadence. ANT+ Dongle, we recommend the Wahoo ANT+ dongle for best results. Check out wahoofitness.com
A Lightning Pin Adaptor is required for iPhone 5/6 and 7 users and new generation iPad users.
Must be 4.3 or better. No ANT+ Dongle required.
If you continue to have difficulty connecting to your device please visit your device’s website to check your device supports Bluetooth and visit www.thisisant.com to check ANT+ support.