... match bit :152,165,178,203 ISO certificate With yeas of experience, now Zhongrui can manufacturer the best quality DTH ... very good price and service.When we start our business of DTH hammer and bit ,you will find that our ... (4 1/2)" REG195-254Love, responsibility and innovationShandong Zhongrui Construction Machinery Co., Ltd.Add: Zhuangjia industrial park, Baotong street, Kuiwen district ,Weifang ...