Flash Grenade

From: Throwables
Chapter: C1 · Lanshiang: Streets, Rooftops and the Hostage Tenement

Power: 1 (stun only)
Per slot: 5

How to get it

Picked up in the field (common). Fixed ones in Chris Chapter 1 (1-3 Rooftops): 4 in the upper-left corner of the first rooftop and 3 on the low platform of the last one. Jake Chapter 1: 2 in the briefcase in the cabinet. Jake Chapter 2: 2 in the box in the FOS Memory Device C shack, with 4,000 SP.

Verdict

Kills Mesets instantly and stuns Strelats, flying J'avo and Haos: keep a couple for Chris Chapter 5.

Exclusive

Chris's and Jake's campaigns.

Many B.O.W.s that hatch from chrysalids are weak to the flash.
It doesn't work on the Rasklapanje.
Haos (Chris Chapter 5): a flash stuns it instantly; run behind it and shoot one of the growths.
Finish What You Start achievement: blind a group and coup de grâce 2 or 3 before they recover.
The Mercenaries: Jake (default), Sherry (costume 1) and Ada (costume 1).