Based on this product's specifications, here are some alternatives and similar models
Wired door/window sensor SATEL K-1 2E — brown, 20 V input, 10 g
Summary description:
SATEL K-1 2E is a wired door/window sensor designed for monitoring the open/closed state of doors and windows. It connects via a wired interface, has a 20 V power supply input and weighs 10 g. The brown enclosure suits installations where a discreet colour match is required. Typical use cases include alarm systems, access control and perimeter monitoring.