The max_weight_500.zip file you have requested: Modifications / Single Player / M to N Titles / CLEAR SKY - Carry More (v3) - 11kb 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:
For more information on Stalker, visit Stalker.filefront.com This mod allows you to carry a maximum of 500kg, as apose to 50kg.