There has been discussion about what to use for keeping up with your four legged buddy while he is trying to recover the wounded deer. Me personally I have tried several techniques, bells, weed eater string and GPS systems. Well I am here to tell you the GPS system is by far the way to go. The GPS systems are pretty pricey but they are worth every penny when you need to locate your dog. The GPS system I use is the Garmin Astro 220 and 330 with dc30 collars. This is a very impressive system. I will tell you I still put the small cow bell on my dogs, you never know with electronics. I will say my Garmin has never let me down but if it does I will still have some sort of location device on my dogs. We all know that it is not practical for all hunters to run out and spend $700.00 on a GPS tracking system. Use the cow bell, they are great and make a lot of noise. I tracked for several years before I was able to spend the money on the GPS systems. Another tool I would recommend for hunters to keep with them at all times is a medical bag with things such as, vet wrap, peroxide, neosporin, baby aspirins, cut and heal (liquid), liquid Tylenol, gauze pads, bottle water, collapsible water bowl, extra leash and medical tape. This is just a few things I keep in my bag. I bought my bag from Harbor Freight for $3.00, and most of the other items you can get from the dollar store. You just never know when your dog may be injured. An aggressive wounded deer can cause a lot of bodily harm. I have had to use my medical bag several times.