... , elevated sprocket, track-type bulldozer, produced by CATERPILLAR technolog. SD7 / SD8 / SD9 BULLDOZER: with semi-rigid suspended, elevated sprocket, track-type ... optional accessories.SD7, 220HP, 28000kgs, straight-tilt blade, ROPS cabin;SD8, 330HP, 40000kgs, straight-tile blade, ROPS cabin;SD9, 430HP, 49000kgs ...