The fuel tank is a one piece PETG 3D Printed insert that attaches to the original Bakelite power truck platforms for non-powered models i.e., no motor or drive mechanism within. In order to assemble this into the model engine, you will need a #43 tap drill bit and a 4-40 tap to thread the 4 pilot holes. The built plate support material will need to be removed before drilling and tapping. The fuel tank ships with 4 4-40 brass flathead countersunk slot machine screws by 1/4". Some clean up of the tank may be required before installation. This piece for sale is for the F3 or F7 un-powered A & B Units. I have found working with these models over the years there are slight variances which is particularly evident more so with the F A Units where upon examining for example the power truck platforms, a little sanding along the edges would have been done on the Bakelite or widening of the screw holes. I have taken inside measurement samples between the tank aprons across all my engines and in my case the B units always come in at approximately 42mm wide. My A units measure any where from 41mm down to 40 mm wide. Consequently, if this kit is used on an A unit that is less than 42mm, some sanding equally of both sides should be done slowly and carefully so the tank fits snuggly into place. The platform the tank mounts to should not require sanding as it sits higher up inside the body without any constraint. Printed with PETG filament available in Black or Froggy Gold, sold as is straight off the Prusa Printer built plate, all sales final no returns. Made In The USA.