As many other reviewers have noted, this mount does NOT fit all or even most eTrex GPSrs. I bought this with my nice new eTrex 30, hoping I could mount it to my bike. Nope! Back doesn't come anywhere near fitting the new 10, 20, or 30 models. I think someone (?) should rewrite this ad to indicate exactly which models it DOES fit. And since the cost is low, it is not worth returning. I would hardly get enough to cover postage, and I don't love the USPS enough to just GIVE them my money! Sorry, Amazon, someone (you or Garmin) dropped the ball on this one!