Help me find this enclosure type!

I have a mental image of what I need, but totally unable to find what it's called! Years ago I used this product. It is simply a two-part system to build metal enclosures on a PCB. I don't mean an enclosure to put a board inside, I mean something like an RF shield box on a board. The first part is a long strip of sheet metal with pins and notches at regular intervals. You fold it by hand into the desired size, being careful to match the final size to a standard lid size. The lid is simply a flat piece of sheet metal with tabs bent down to form a lid, which squeezes onto "clasps" on the strip. The strip is soldered to the PCB, and the lid can be installed and removed by hand. It was cheap and it looked cheap, but it worked quite well IIRC. Please someone help me locate these guys again! TIA