These durable, thin walled, flexible stainless steel hoses do not alter or crack like rubber or plastic hoses and do not collapse under vacuum, have less connection parts and therefore introduce less possible leaks in a vacuum system. NW/KF Flexible Metal Hoses are made using 304 Stainless Steel and may be cleaned with solvents. They have a thickness of 0.006" TheNW/KF 16 has a 3/4" internal hose diameter Uses common NW10/16 clamp connection These were part of an assembly for a brand new sapphire production facilityin Silicon Valley that was never commissioned. This part has never beenused in production. Missing the original packaging.