Another vote for the Garmin. I have the TT15 model Alpha with two collars and I use them on my Harriers and GSP's. They work great and are easy to use. Batteries last a long time too.

Best,

Chet

The first great thing is to find yourself and for that you need solitude and contemplation. I can tell you deliverance will not come from the rushing noisy centers of civilization. It will come from the lonely places. Fridtjof Nansen