The Perfect Seal fittings stand for, as the name implies, a perfect seal with 3/8" tubing.
Note for watercooling beginners:
The connectors for imperial hoses(7/16“, 3/8“, ½“) are provided with measurements in mm in our shop. These can differ by +-1mm, which is no problem as hose clamps have to be used for installation. If the hose is to be mounted without a clamp, a larger fitting should be chosen. With some fittings that tend to be larger, it is possible though that a hose with an inner diameter of 13mm actually does seal without a hose clamp.
Material: Silver nickel plated brass
Thread length: 6mm
Compatible with hoses with an inner diameter of 10mm (3/8")
Fitting inner diameter: 10m
Upper outer fitting ring: 12,4mm
Middle hose contact surface: 11.6mm
Key width: 16mm
10mm (3/8“) hose clamp: up to 8mm none, from 10mm up required
10mm (7/16“) hose clamp: up to 8mm none, from 10mm up required
12mm (1/2“) hose clamp: up to 11mm none, from 12mm up required
13mm (1/2“) hose clamp: up to 11mm none, from 13mm up required