The Siemens 5UB1551-0KK is the no-claws variant of the 5UB1551 electric white Schuko socket outlet. Rated at 10/16 A / 250 V AC for flush-mount indoor installation, it shares all technical specifications with the base model — screwless plug-in terminals, 55 × 55 mm cover plate, no labeling field, no increased touch protection — except for the mounting method and packaging quantity.

What does "without claws" mean in practice?

Standard DELTA i-system sockets use retractable metal claws that swing out behind the plasterboard or drywall as you tighten the mounting screws, clamping the socket against the wall surface. The -0KK suffix ("Keine Krallen" — German for "no claws") removes these claws. The socket is secured by screws driven directly into the flush-mount wall box. On a solid substrate — brick, concrete, or blockwork — screw fixing into the box provides a firm, stable mount without needing the claws. The socket is also slightly lighter (approximately 70 g vs 78 g) because the metal claw assembly is omitted.

Solid wall vs drywall — which mounting type for which substrate?

For plasterboard or drywall installations, choose the clawed version (5UB1551 or 5UB1551-0KE). The claws grip behind the board and prevent the socket from pulling forward when a plug is withdrawn. For brick, concrete, or blockwork walls where the flush-mount box is set into solid material, the clawless 5UB1551-0KK is ideal — screw fixing alone holds securely, and omitting the claws simplifies installation. Using a clawed socket in a solid-wall box can actually be counterproductive: the claws may not deploy correctly in a rigid box and can interfere with seating the socket flush against the wall.