Hey, if you're working on air systems, fuel lines, or low-pressure hydraulic setups, this flexible black nylon hose is a solid pick. It's got a 3/16 inch outside diameter (OD), which is about 4.8mm, and the inside diameter is 0.1 inch (2.7mm). You get a full 20-foot coil, so there's plenty for most projects. This stuff is designed to handle vacuum, air, oil, fuel, and low-pressure hydraulics, and it works with 120 Series push-to-connect aluminum fittings. The inner surface is super smooth, which helps with flow and reduces resistance. It's abrasion-resistant, chemical-resistant, and lightweight, but still tough enough to handle under-hood temps and everyday wear. Perfect for DIY car repairs, pneumatic tools, or any situation where you need a reliable, flexible tube that won't kink easily. Honestly, it's way easier to replace a section of failed hose than redo a whole assembly, and this nylon hose makes that job a breeze. Good quality for the price, and it gets the job done without fuss.