Specification :

The eTrex Summit was designed for both marine and recreation use. This all-in-one navigation device for the outdoor enthusiast is the first combination GPS, altimeter, and electronic compass. The electronic compass provides bearing information when you're standing still and the altimeter determines precise altitude, so you can tell how high you've climbed and your rate of ascent.
Like its predecessor, the eTrex Summit boasts a powerful 12 parallel channel GPS receiver and comes packaged in a small, sleek case with operating buttons located on either side of the unit. The case is completely waterproof to withstand immersion in one meter of water for up to 30 minutes.
The eTrex Summit: It's what the hard-core outdoorsman has been waiting for.