Bentonite or similar material may be used to advantage in rocky terrain. Where holes are bored for the insertion of vertical electrodes or where strip electrodes are laid radially under shallow areas of low resistivity overlaying rock strata, bentonite packing will increase the contact efficiency with the general mass of ground. We, at Atul Casting and Metal Works manufactures all earthing related products such as G.I Strips, G.I plates, G.I Rods, G.I Pipes, C.I covers, Cable Trays, G.I Wire, Manhole Covers and Route Markers for past 50 + Years in heart of New Delhi. Call us at +91 9873361672 for best deals