When the mine is deployed with the chemical fuze it is very difficult to detect because the only metal in the mine is the detonator capsule. There is a secondary fuze well on the bottom of the mine that can accept a fuze allowing remote command detonation of the mine.
The mine is designed for stealth and remote detonation, relying on a single metallic component (the detonator capsule) for activation.  A secondary fuze allows for controlled detonation from a distance.