Making a light saber extend and retract on button push

Hey guys. Got a question. How do you make a lightsaber extend and retract upon the activation of 1 or 2 buttons?
I'm looking for the quickest way to get it to extend and retract.

I know there are some toys out there that might do this...but I'd like to have someone tell me which ones they are before I waste my money on 5 or 6 of them.

Thanks in advance!

 

I know of none that retract but the latest Hasbro sabers have a button for extend.

Of course if you are just referring to the light inside the blade and not the physical blade itself, almost all of the Master Replica Sabers have both extend and retract as well as the HyperBlade lighting system for custom hilts. The HyperBlade from Hyperdyne Labs is quite expensive though.

 

Nope, I'm talking about the blade itself. I'm actually trying to make a set of Wolverine claws that extend and retract.
Good to know that the Latest Hasbro sabers extend but dont retract. Doing both is really necessary for what I'm thinking of so I guess using these would be a dead end.
Thanks!