This is a well-made, fairly easy to use flexi-leash.  What I don't like about all flexi-leashes is that it teaches the dog to pull; therefore I won't be using it.  However, for those of you who like flexi-leashes, this is a well-made, one-button leash for large dogs.  The unit is kinda heavy, but has to be if you're walking a 100 lb. dog.  I never really got used to the button for stopping and holding the leash because I used it 3 times before putting it away.  I have trained my dogs to walk without pulling and by the third time on the flexi-leash they were all starting to pull--not good.  I will go back to carrying a 20 ft. training lead for when they want to off-road; it's not nearly as heavy and I have an easier time on recall. The 4 stars rating is because it is well-made, retracts quickly but is heavy.