Based on this product's specifications, here are some alternatives and similar models
Window/Door Contact Eltako FFKB-wg Wireless (model 30000423) — battery-powered wireless sensor for contact monitoring
Summary description:
Eltako FFKB-wg (30000423) is a wireless window and door contact sensor designed to detect open/closed states. Battery-powered and intended for integration into wireless alarm and automation systems, it transmits contact changes remotely. Use it to monitor windows or doors for security, energy management or smart-home automation, providing reliable state reporting without wired installation.