supply of 4 leg twin path round slings with check fast external warning indicator and fibre optic inspection system of 16t swl, 3.5 meters length as per american standard-ansi/asme b30-9 and international standard iso4878 along with the following facilities. 1) polyester twin path round sling having 20 ton capacity master o ring with 2 meters circumference length. 2) polyester twin path round sling having 2 nos. 10 ton capacity sub o rings of 1 meter circumference length. 3) each sub o ring is fitted with 2 nos of twin path round slings with check fast system, overload indicators, each sling of capacity 4 ton, each 2 meters effective length and each sling is to be fitted with anti abrasive sleeve at touching points. 4) each sling is to be fitted with 9.5 ton capacity of d shackles with eye hook. make: simplex or its equivalent.