File extensions: .m3d .c3d .igs .sat .stl .stp .wrl .x_b .x_t GOST 12820-80 Full compliance with the original dimensions. Very useful when designing pipeline systems, etc. One of the pictures shows an example of the use of flanges in a 3d project. I can make custom models of fittings for pipelines and much more. Any level of complexity and detail.