supply of supply of ferric alum black as naked slabs with 15-16% of alumina content, 0.5% insoluble matter, 0.5-0.7% of iron fe including cost, conveyance to dept stores, loading and unloading for the maintenance of water supply.supply of ferric alum black as naked slabs with 15-16% of alumina content, 0.5% insoluble matter, 0.5-0.7% of iron fe including cost, conveyance to dept stores, loading and unloading for the maintenance of water supply.,supply of ferric alum black as naked slabs with 15-16% of alumina content, 0.5% insoluble matter, 0.5-0. 7% of iron fe including cost, conveyance to dept stores, loading and unloading for the maintenance of water supply. [quantity tolerance (+/-): 5 %age , item category : normal , total po value variation permitted: max 8 lacs ] ] => limited