CYCPLUS C3 Cycling Speed Sensor & Cadence Sensor, more details here:
https://www.cycplus.com/products/cycplus-smart-speed-cadence-sensor
BLUETOOTH & ANT+ MULTI-PROTOCOL
CYCPLUS bike speed sensor supports all kinds of equipments and applications, such as martphones, tablets, and bike computers by Wahoo, Polar, Garmin, and more, which collect speed or cadence data via Bluetooth or ANT+.
Track and capture real-time cycling cadence on your bike computer or smartphone with compatible training apps.
Works with 50+ Smartphone Apps including Wahoo Fitness, Zwift, Trainerroad, Sufferfest, MapMyRide, Komoot, RideWithGPS, Cyclemeter, Peloton, Rouvy, Fulgaz, Kinomap.