Q-Grip Slip Resistant Canterbury Style Decking with Gripdeck Technology is made from high quality FSC certified softwood. Its finished size after machining is 27 x 144mm. It has been tested to BS7976 parts 1 & 2 and provide a 'low potential for slip' under classifications set out by the UK Slip Resistant Group. It is preservative pre-treated with Tanalith E Extra giving the timber water repellant properties. Canterbury deckboards have 7 grooves with gripped insert strips that fit into the two second most outer grooves.