What is this type of magnification tool called?

Ok, when I was a kid, Mum and Dad bought me a telescope set which I had great fun with. After a while I got frustrated with the thing shaking when I was using it and I lost interest in it a little and stopped using it. However, there was one part of it which I was playing with and I noticed that it worked as a microscope! I want to know what that piece is called as I want to buy another one.

The piece was a 12cm long hollow cylinder with an eyepiece on one end and a clear plastic rim on the other end. When I pressed the plastic end onto something, it was focussed as a microscope. It was brilliant. I can't buy this think again because I don't know what it's called.

Please help.

Ant...