Review on Garmin Astro 900 Dog Tracking Bundle: GPS Sporting Dog Tracking for Up to 20 Dogs with Handheld and Dog Device by Marina Smith

I researched all the collars on the market before committing decided for this one. I live in a rural area where lots are approximately 2 miles by 2 miles. There are no roads, only trails to neighborhoods of pine plantations, deciduous forests and glades interspersed with farmer's fields. I wanted to keep my dogs at home especially during hunting season. We breed raccoon greyhounds, so they are natural hunters who are difficult to keep up with. I bought three collars and it paid for itself on day one. Caught the dogs coming onto the road after a 1.5 mile chase. I could see on the part where they were how quickly they closed the gap and waited on the road when the deer came out with them right behind them. If I hadn't caught them I would have carried them 2 miles the next time they crossed another road. Can't verify at what range they work, but at 2 miles in dense bush they worked fine. The Garmin product does not depend on the rather poor phone reception here, but uses the GPS system. The device does a lot more until I figure it all out, but it does what I need it to. I mean, tell me where the dogs are anytime. Setting the radius or boundary will let you know when the dog will walk away so you can stop it before it gets too far. The device and the collars are not cheap, but they are well made and worth the money.