Caldwell's Pet Supply Co. Original Running Leash

Great leash but the clasp for the collar broke easily.

I've had my OG Original Caldwell leash (spring loaded clip that attaches to collar) for over 6 years and it has outlasted 4 other brands. This leash has been dragged against mountains and around sharp rocks, covered in snow, dirt, and mud, and dunked in the ocean countless times and it still looks new. I was afraid the plastic buckles would break, but so far, no issue. I use this on a 45 lb hound/cattle dog mix who runs races with me as well as on a 65 lb solid muscle Lab/Dane/Border Collie mix (who broke 3 other leashes in a matter of days). Unlike other brands, I can quickly adjust the waist size with 1 hand, which is helpful when running in layers. I can also shift the leash to the side without moving the waist band. The length is also quick and easy to adjust with 1 hand, though the leash does tend to loosen easy as others have mentioned. I like the easy release of the buckle that attaches the leash to the waist band, especially when descending steep mountains where I need to quickly release my dog from my body for safety. This also converts it to a hand held leash. And the nylon is durable without being too thick. This allows me to wrap the leash around my hand if I need to pull the dogs closer. I'm ordering a 2nd Caldwell's and noticed the clip from the leash to collar is different. Hearing that this has slid open in other reviews, here's a solution: attach a small locking metal carabiner (a few dollars at a hardware store) to the metal ring that attaches the nylon to the clip. Lock this around the metal ring of the collar or harness. For harnesses that only come off if you detach the leash, this isn't as practical. But it works as an extra precaution, especially if the carabiner is made to hold heavy weight. (Do NOT use a key chain carabiner that is not designed to hold weight). Hope that helps! Now that I'm reviewing, I'll actually be purchasing 2 more of this leash. It's that good!