Customize stiffness and impact level by adjusting air pressure. Easy inflation: One-way check valve incorporated in Inlet to help prevent air from escaping while inflating. For best results: 1) Press back of inlet to help establish the seal prior to initial inflation. 2) Inflate, and hold finger over inlet for a few seconds. This gives the check valve time to rest and seal, and helps maintain air between breaths. 3) Close valve, wait a minute or so for the plastic to relax, and inflate further to desired firmness. To deflate: Pinch base of valve. This opens valve and allows air to escape. Swords do not light up. Double Blade Dimensions: Length: 49" Handle length: 12" Handle: 2" diameter