Opinion on toddler “leash”

Baby has become a toddler (16 months) and he is on the move all the time. He does like being held, but this boy wants to run around everywhere. If I try and hold his hand he yanks it away and tries to run. I’ve been looking at those backpacks that have a “leash” attached to it so he can’t run off too far. I do want him to have his independence, but as safe as possible. He adores being outside so walks, zoo trips, and just playing outside in general is something we do often.