Nightwing BTAS grapple gun

I am a huge fan of Nightwing of course. So I had a replica of the Grapple gun designed taken from the Batman animated series. Designed from a good buddy of mine, Tom over @ ClevelandFX design a working Pneumatic grapple gun! With a hefty price, I had detachable grapples hooks designed with monofilament spools. Its really cool! The only thing it doesnt do is retract. I'm open for comments and advice. Thank you.