This is 50' but is the best long leash I have used. Incredibly durable and I really like that it's so visible. (n/a)

http://smile.amazon.com/Best-Long-Dog-Leash-Training/dp/B003EH2XJ2/ref=sr_1_2?ie=UTF8&qid=1463110246&sr=8-2&keywords=best+long+dog+leash