These wrist bands appear to be of the ordinary sort, but they have the power to enable the wearer to move by brachiation—swinging from one tree limb, vine, etc., to another to get from place to place. 

The power can only be employed in locales where these sorts of hand-holds can be found. 

Movement is at a rate of 3", 6", or 9" - the more jungle-like the conditions, the greater the movement rate. 

The wearer is also able to climb trees, vines, poles, ropes, etc., at a rate of 6", and can swing on a rope, vine, or other dangling, flexible object as if he or she were an ape or other sort of simian.

Also, if the wearer desires, he or she can leap and jump as if wearing boots of striding and springing, but the jump must culminate in the grasping of a rope or vine, movement through the upper portion of trees, the climbing of a tree or pole or some other activity associated with brachiation.