Other Products Custom J beads and End Caps Sometimes thicker wall types on site can dictate the sizes of our metal trims that go with our cavities. We’re able to provide any internal measurement to suit your specific wall types. Maximum lengths are 3000mm. Flat Aluminium Skirting High Quality aluminium 1.6mm skirting boards in Mill, Natural anodised and powdercoat finish. Length 3.6 Metres.