Use with traditional Butyrate Round Tubing for piping systems found in industrial and commercial modeling, and for residential plumbing in dollhouse models. Also useful in model car roll cages, exhaust systems and scratch built chassis. Ideal for stimulating creativity in educational programs utilizing our D & T Packs. Fitting design allows temporary press-fit assembly, however final assembly must be cemented. Precision Injection Molded in Butyrate Plastic.