A cheap nylon or cotton leash. I don't use leather on puppies until AFTER they stop chewing on the leash. A leather leash can't handle much chewing before it is useless. Nylon and cotton hold up MUCH better.
I would also think about getting something shorter than 50 feet. (but longer than 6 feet.)
50 feet is a LOT of "line", especially for a puppy, to get tangled up in. If you don't want to spend a bunch of money, you can always just buy some smaller rope and use that. Around here the thinner rope is only .19 cents a foot, and a snap is around $2, so it is a lot cheaper to just make your own. And that way you can make it any length you want.
I would also think about getting something shorter than 50 feet. (but longer than 6 feet.)
50 feet is a LOT of "line", especially for a puppy, to get tangled up in. If you don't want to spend a bunch of money, you can always just buy some smaller rope and use that. Around here the thinner rope is only .19 cents a foot, and a snap is around $2, so it is a lot cheaper to just make your own. And that way you can make it any length you want.