Gem Bids For 178 Ahu Prefilters Of Size 500wx405hx45mmd As Per The Attached Annexure. Ahu Prefilters Of Size 430wx560hx45mmd As Per The Attached Annexure. Ahu Prefilters Of Size 420wx455h X45mmd As Per The Attached Annexure. Ahu Prefilters Of Size 435wx455hx45mmd As Per The Attached Annexure. Ahu Fine Filters Of Size Flange Size- 610mmx610mm As Per The Attached Annexure.