FTC: Affiliate Disclosure: All links pay commission
This is how Optical HR work as explained by Dr Steve from Valencell for in-ear usage.
Valencell make the technology for JABRA, SCOSCHE and others.
This content is not sponsored. It’s mostly me behind the labour of love which is this site and I appreciate everyone who follows, subscribes or Buys Me A Coffee ❤️ Alternatively please buy the reviewed product from my partners at their regular price. Thank you! This really is reader-powered content.
FTC: Affiliate Disclosure: All links pay commission. As an Amazon Associate, I earn from qualifying purchases.