The Siemens 5SL6140-7BB is a SENTRON miniature circuit breaker — a single-pole unit with a C tripping curve, rated 40 A, and a breaking capacity of 6 kA per both EN 60898 and IEC 60947-2. It's built for residential and infrastructure branch circuits: lighting, socket outlets, general-purpose loads where the inrush isn't extreme but you still want the C-curve's moderate magnetic trip threshold.
The C-curve trips magnetically between 5 and 10 times rated current (200–400 A for this 40 A unit), which suits motor-starting and fluorescent-lighting inrush better than a B-curve would.
Sealable design allows locking the toggle to prevent unauthorized operation.