The black_chaser_13.rar file you have requested: Clear Sky / Mods / Weapons / Black Chaser 13 - 2.47mb is not available. Perhaps try browsing all files for the game S.T.A.L.K.E.R.: Clear Sky and upload any files you want to share or are missing. This is the only information we could locate:
This mod changes the Chaser shotgun in the game to have a new skin. See the screens below.