PlugPack Power Supply AC pins cover

I do a lot of arduino projects and I've found that the little AC power to USB power supplies are a cheap and convenient way to provide 5V dc for the projects. I've made this little cover that goes over the AC input pins. Both PLA and ABS plastics are excellent electrical insulators. I wouldn't use the carbon fibre or flexi filaments.

With regard to the plugpacks, I buy the ones with the US style pins. Then I attach some crimp on tab style connectors. This cover slips over to provide insu