Einbau-Tür-/Fenstersensor

The install took a bit of patience, but once it was set inside the frame, you genuinely can’t see it at all—my hallway finally looks clean without those bulky plastic boxes. It triggers reliably every time the door shifts, and the zero-visible-hardware part is exactly what sold me.

Boring install but worth it—the sensor fits flush inside the frame, so you'd never know it's there. Security-wise it's been flawless for the past month, no false triggers even with the door sagging a bit.

Used it to secure the back door and you genuinely can't see anything from the outside. The recessed design sits totally flush inside the frame, so it works without that ugly plastic bump on the trim.