Our stainless steel bore caps are manufactured by us in Australia, they will not rust.   The standard bore cap will safely fit all bores with a bore casing internal diameter of 220mm or less and this model has a 50mm female BSP thread in the centre together with a slot for cable access.   We laser cut the round plates from 304 stainless steel sheet, brush the face so they are neat and burr free then we attach the 1 x 50mm stainless socket and 1 x 50mm stainless steel elbow with a length of 316 stainless steel allthread secured with chemical weld.   The load rated cast steel eye bolts are secured with the locked on M20 nuts and the complete unit is then packed ready for dispatch to you.  The galvanized steel chain is easily secured to the eye bolts using the 'D' shacles provided, the chain is the extension end of the nylon safety rope that is secured to the chain on one end and the pump on the other.   This new revised bore cap is much safer & easier to lift out, the stainless steel will not rust and comes with a 25-year warranty.