Red Flares

Red Flares are part of Lara's gear in Tomb Raider Legend.

from the official site

Back before light sources became more portable, reliable, and resuable, flares were the standard for lighting up the interior of dark tombs. Lara's favourites were always single use stronium nitrate flares with a plastic wind resistant cap for easy lighting.

(They are used near the end of the second level while Lara is having a flashback, in Tomb Raider Legend).