I have a co pup.7 months old now. it is not only for distance but also example he is barking in my yard and i say enough.normaly he comes inside than but when he doesnt would it be maby easier to correct him.Its too expensive to trie it out.So i was oping on people here with experience with it by an LGD. I also think that when two dogs stand next to eachother being dominant it is useless to use it to call him back and use the e-collar.I think that because they use a very little trigger to attack eachother when they stand in such position and i think the e-collar can be the trigger at that point. Once i made a mistake.My gsd was right over a rottie.Both needed very less to attack eachother.I was standing beside them and normaly when i say come on my dog walks further.he didnt now so i hitted my dog very soft with my foot to get him out of the trance and the moment i touched my dog he attacked.Stupid from me i should have just walked further but during the years you learn :D i think the e-coallar can be that trigger too. There are some situations that i think it will be a help but if it is worthy to buy it for that i dont know.