Garmin eTrex Legend mounting screw
 

Not sure if this has been said before but if you own a Garmin eTrex GPS and use the "rail mount adaptor"
(this one - https://buy.garmin.com/shop/shop.do?pID=1056)
to mount it on your bars, make sure the screw that holds the clip to the back of the GPS is loctited in.
Mine kept vibrating loose and I eventually lost it somewhere between Novosibirsk and Omsk, it wasn't a happy day.....