About this 3D model

Strong yet simple design. It is curved to add extra strength, the top/bottom printed in a concentric pattern, and the internal infill set to rectilinear to bond the layers better. It takes about 4m(12g) of filament, and I recommend using PETG as it should deal better with constant load. The internal gap measures 40,2mm so it should fit 40mm doors easily. It does fit mine which are ~39mm.