A black silicone hose sold in bulk by the decimeter (10cm segments) at 51mm (2") inner diameter, for use in custom-length turbo, intercooler, and vacuum plumbing. do88's own catalog lists this exact article as "SL51 - Silikonslang Decimetervara Svart 2'' (51mm)", their straight bulk-length hose stock rather than a pre-shaped hose.