The 200 ft Tumbo trolley we installed was easy to install (2 ladies did it) and it is saving an adoption for a dog that has been in our shelter for over a year!!! The potential adopters LOVED her but when they opened the door she bolted and was gone for several hours. She was going to get hurt or killed in the massive wooded area or had to go back to the shelter. The trolley was her only chance and it is working !! Fancy gets to stay.