we have tried just about every collar out there over the years. stick with the sportdog 2400 or the d.t 200 series. the dogtra collars are from a companysplit at d.t. so they are pretty much the same collar.we use them on beagles and they are very hard on a collars. we have bench leg and shorter beagles. they are constantly banging the collars on rocks ,stumps, in the dirt you name it. these are theonly ones that have lasted. we use ours 5-6 and many times 7 days a week. there are 100's of hours on these collars without any major problems. the d.t.'s have been sent in a couple of times but the turn around is about a week. never had a problem with the 2400. also don't buy any collar that does not have a warning mode.warning mode beinga vibrator or toner on the collar. any collars with out these options is already out dated.