Separate Polar H9 sensor from strap for battery life? : r/Polarfitness

Polar heart rate sensors

Polar H9 Bluetooth & ANT+ Heart Rate Transmitter (Center Piece Only)

Polar H10 Never Looked So Good

Polar H10 Heart Rate Monitor: Very Long Term In-Depth Review

Polar H9, Affordable heart rate monitor chest strap

Polar Vantage V2 review: Not enough of an upgrade

Polar's New H9 Heart Rate Strap: Everything you ever wanted to know

Best Polar Heart Rate Monitor H10 vs H9 vs Verity Sense — PlayBetter

Polar Vantage V2 review: Not enough of an upgrade