Now we need to make the case of the filter. The easiest way and the way we will do it is, to get a case of another filter which we dont need, or which is useless. Now it is importand, that we get a case, what is openable. You can see that is it openable if it has 2 small notches on it frontside. Otherwise it may is glued, what means it is not useable for us.

Remember to get a case what fit onto your lens!