Technical Parts are usually internal and designed for a specific function. Common technical plastic parts are mounting clips and brackets, spacers and shims, insulation blocks and posts, etc. These usually require tighter tolerances than covers or housings and typical uses include tool and specimen holders, tube and cable management clips, low friction washers and pads, electrical insulators, guides and bushings, spacers and dampers. Materials used are ABS, PC-ABS, PC, PVC-ABS, HDPE, UHMW, Acetal (Delrin), PA (Nylon) and others.