A proximity fuse is an electronic device that allows a projectile to be exploded within range of a target. For boots-on-the-ground soldiers, this weapon would be invaluable to their success and safety.

RADAR, SONAR, the proximity fuse,

No, it's not a wrench. It is an adjustable proximity fuse used in artillery. Now superseded in modern armies by an improved version.

A proximity sensor is designed to detect when something comes into a given range of the object in which it is installed. For example, car manufacturers are beginning to use proximity sensors in car bumpers to aid drivers in parallel parking. When a vehicle is maneuvering and comes near another parked car, it gives off a warning.

In naval warfare, submarines fire torpedoes which are wired with a proximity fuse which will detonate the payload when the weapon gets near the target.

The warhead in some missiles is configured with a proximity fuse which is designed to detonate the payload when the missile reaches a preset distance from the target.