For this throw, press and release both mouse buttons at the same time. The flash should blind every position in Middle and leaves enemies at Elevators a no time to react. On the flipside, especially from the Window position, but even from CT it's relatively easy to spot.

Was used by SH1RO against G2.

Alternatively—or additionally—, use this flash that works as a nasty pop flash for Window and CT, but might not catch Elevators.