The safety adapter can be fitted into all Ø 4 mm sockets. This ensures compatibility with safety measuring leads with rigid sleeves. By screwing a locking screw (SW 1.5) into the splay plug. The safety adapter can be tightly connected to the Ø 4 mm socket. The safety adapter can then no longer be removed without tools. Contact parts: nickel-plated. Insulation: PA 6.6 (Polyamide).