The Gerber Index Knife deploys in one of two ways: with thumb studs or the finger flipper. You can see a few more photos of the knife on Gerber's website, which may give you a better idea, or you can take a look at this YouTube review of the knife where the host shows how to deploy it. This item is only available to purchase online (not available in stores). When you place it in your cart and select your shipping option, it should tell you what the anticipated delivery timeline will be to your location.
Hopefully this helps, thanks!