Based on this product's specifications, here are some alternatives and similar models
Magnetic Contact Sensor SATEL B-2FL – cylindrical door/window reed switch, model B-2FL
Summary description:
Cylindrical magnetic contact sensor SATEL B-2FL (reed switch) for monitoring doors and windows. Compact cylindrical form factor with magnetic activation provides simple normally-closed or normally-open wiring for burglar alarm and access-control systems. Designed for discreet installation on frames and sashes to detect opening/closing and integrate with alarm panels and security devices.