These rubbers are new old stock and have never been used, they were originally manufactured to run inside army tank tracks. The centres have been cut out (see pic). We have used this type of tyre fitted to our traction engine - turn out the centre, cut them and have them rolled to the appropriate radius or fitted to a trailer or commercial vehicle. We have also cut them into strips and fitted them in the style of 'strakes'. Vastly cheaper than new tyres! They have cast into the rubber 'BTR 31.2 x 5.0 x 1.9' Dimensions: width of steel 6". outside diameter 31". inside diam of steel rim is approximately 25.5" but this could be turned down to around 24.5" if required. I have 17 of these for sale at £100 each or £1,500 for all 17. Collection or I can have them delivered on a pallet at extra cost.