supply of aluminum extension and straight ladders as per is 4571/1977 or latest.aluminum extension and straight ladders as per is 4571/1977 or latest.,aluminium extension ladder as per is 4571/1977 or latest, closed height : 06 mtrs, extende d height : 11 mtrs ,aluminium wall supporting extension ladder manufactured from aluminium c shape sec tion of size- 66.6 mm(l) x 31.7mm (w) x 3.5 mm (t) confirming to he - 30 grade t-6 temper as per is: 733 and aluminium 25 mm diameter non slippery round corrugated tubing fitted with heavy duty safety lock , nylon rope and pulley and rubber pads at bottom and top end. twist proof and unbreakable performance. make - s j ladders, king , techoscient, sumer , safal or similar [ warranty period: 30 months after the d ate of delivery ] ] , aluminium straight ladder 8 meter with hook on top as per is 4571/1977 or latest. the stiles of ladder should be made of alum-c section size 66.6/31.7/4mm while the steps mad e of heavy duty aluminium fluted pipe diameter 1 inch corrugated non slippery are fitted at 12 inch (300mm) interval. the top and bottom end are fitted with rubber steps strong enoug h to support at a time. make - s j ladders, king , techoscient, sumer , safal or similar [ warranty pe riod: 30 months after the date of delivery ] ]