A Screwtop is a robot Petpet, which according to the Neopets site, has a tool kit in its head and are always male. You can buy them here or through the Shop Wizard. The Screwtop can only be painted Faerie.
Weight: 12 Ibs
Estimated Value: 15970 NP
Description: "Screwtop is a fairly simple robot...he has a toolkit hidden in his head, and is helpful when doing DIY."