HEAVY DUTY TO CARRY UPTO 40 TONNES Lockable, Zero Theft Value NIL composite manhole cover systems have zero theft value and are unattractive to thieves. NIL products feature a variety of security and retention which are optional. The worldwide price of scrap metal has increased rapidly and is forecasted to remain at a high level. Metal products used in infrastructure applications are disappearing all over the globe. Theft challenges utilities and municipalities; open access vaults and sewers are a public danger, exposed infrastructure is vulnerable to damage, and it is costly to replace the stolen equipment. The weight once thought to be a theft deterrent has become the principle factor attracting thieves to iron manhole covers.