PRITHVI SERIES are 4th generation Hammers, we eliminated Foot Valve in the Button Bit which is the potential troublemaker when the drilling is in deep depth. The Proprietary Dynadrill's "PRITHVI SERIES HAMMERS" Maximizes efficiency and develops greater power for any compressor capacities available. As a result, the Prithvi series of Hammers penetrate 15% to 30% faster than competitive Hammers available in the market giving you an additional production at a lower unit cost. For More Details Visit us: http://www.dynadrillequipment.com/dth-hammer.php Contact us: 9440048236 / 9440609036