These work so well ..... and so many people enquire - I bought a few when they were "on offer" and give them as gifts as people say "where can I buy one ......"
They make some cheapo ones in plastic - but it's essential that they're made of metal.
Yeah, I love mine. Here in the US the original brand name of these was the Rabbit, but there are a lot of knockoffs. When getting one, metal is important, yes. But it's also important to get one with removable corkscrews. The corkscrews themselves get dull with use and don't slip into the cork as easily, requiring replacement.
Still, I usually use the standard, no-frills waiter's friend. There's just something about the process of using it that I like: a modicum of skill, the feeling of working the screw into the cork, the squeak of cork on metal, the satisfying
pop! from using two hands to get at tasty tasty wine...