Without a string.
Stringless things are often easier to use because you don't have to worry about the string getting tangled or caught.
Examples:
The kite is stringless, so it doesn't get tangled.
I like the stringless balloons because they don't get stuck in trees.
She prefers stringless headphones because they are easier to use.
The stringless yo-yo doesn't get all twisted up.
The stringless guitar is easier to play.
I wish all my toys were stringless.