Manufactured from tough impact resistant thermoplastic which provides strength and durability. Enclosures are fitted with 20mm knockouts to accept standard UK conduit fittings. All knockouts include a unique drill start feature for use with 25mm conduit fittings if required. Generous wiring space in the back box. Temperature range -5°C to +40°C (Average value over 24 hour period not to exceed 25°C).