We are offering jack hammer.1.atlascopco b87c, b67c, b47, tpb-90, tpb-60, g10, g20, tca-7, y24, y26, yt24, yt28 breaker2.specific parameter in detailed description b47 breaker adopts mature technology of american chicago pneumatic corparation and advanced double-hammber desigh.the hammber is driven by compressed air to impact the cushioned hammber vertivally and toandfro and the cushioned hammber impacts the driling tool.the breaker features portability, high impact frenqency and high working efficiency.