This is a reuseable accessory to help make model tarpaulin hoods to fit over the 4mm:1ft coil cradles for the Warflat Coil EG conversions. The price of this gadget depends quite a lot on the plastic you select to have it made in. You will have to carefully saw the two formers apart and smooth the points where the sprues attached. To use them, cut two sheets of a suitable thin plastic or paper packaging material to size and fold them as neatly and tightly as you can over these fomers to hold them in the right shape while you glue the overlapping end pieces to each other (not to the formers). The resulting covers should keep their shape when slid off the formers and fit nicely over the coil cradles. Depending on the sheet plastic you use, they may need to be supported with wire or cardboard inside. If you want to save a little money on these, as well as picking the cheapest plastic you can also opt for the hollow version of the same things.