DETONATION DELAY
Delays the detonation of nearby Grenades. Not much useful since if you keep your ears open, you can actually hear the grenades falling nearby and always have enough time to avoid these.
- Upgrade II
Delays the detonation of enemy explosives.
- Upgrade III
Provides an automatic Defenses against enemy missile attacks.

What exectly mean upgrde3 ? It is protection from every weapons like scar/feline/sniper rifle etc etc. or only protection from granades/c4/jaw ?

upgrade 3 only protects you rockets, JAW and only JAW not any other of the weapons, Useful module for crash site

It causes a JAW flying at you to fly upwards, which means it might still end up killing you.

Also, this is only a guess, but it may also affect CEPH attacks. In some situations you see the CEPH missles flying in all crazy directions, and now that I think about it, this module might be why.