Spelsberg terminal block housings in compact construction type are designed in two variants. On the one hand for indoor installation and as a variant for outdoor installation. The RKK terminal block housings come in grey and are equipped with a compact clamp block. Polystyrene was used for the interior installation. In order to achieve industrial grade, RKKi housings have been developed which are also suitable for installation in exterior areas. The manufacturing material used for this variant is polycarbonate. The housings reach IK08 when tested for shock resistance. Knock-out membranes simplify the preparation for required pipe in-leads. Cross connectors, terminal blocks, partition walls or attachment bushes are available as accessories for the terminal block housings. Everything in the usual Spelsberg quality.