The Garmin Foretrex 301 GPS is the scaled down version of the 401. The 301 does not have the electronic compass or barometeric altimeter. Also, the data is not shared wirelessly.
If you don't need those, save some money and go with the 301.
Weighing in at an impressive 3oz. and less than 3 inches long, you can comfortably wear this GPS on your wrist, chest rig and even your primary weapon. Great reception even with canopy and moving fast whether running, driving or riding a bike. Satellite pickup is quick with either of the Foretrex Units.
Will display maps, way points, routes and tracks but not topos. Leave a trail of bread crumbs so you can forget about getting lost. Holds up to 500 waypoints and 20 routes! Need to upload data, use a .gpx file.
Get lost? Use the "Take You Back" feature which takes you on your original track or use the compass to find a quicker way.
Runs up to 17 hours on AAA batteries.
Get the proven GPS from Garmin and be more precise with your data.