Portwest S156 - Trouser Pocket Foam Knee Pads. These knee pads can be used for trousers and coveralls where there is a knee pad pouch for slide in knee pads. Portwest Workwear provides the ultimate in knee protection & wearer comfort. These ergonomically designed kneepads offer durability, comfort & protection. Size: 23 x 16.5cm. Fabric: Ethylene-Vinyl Acetate. CE certified, fits all Portwest workwear with knee pad pockets. High density material provides high levels of protection and will not hinder movement.