Handmade silicone hose sets won't perish, split or contaminate your cooling system in the way ageing rubber systems can. Specification: all hoses are of 3 ply, 4.5 mm wall construction in standard polyester silicone. Hose temperature range: -50°C (-58°F) to +170°C (338°F). Hose max working pressure: 3 ply = 5 bar (70psi), 4 ply = 8 bar (112 psi). Size tolerance: +/- 0.5mm.