DH-AQJT Safety Joint  Application  Ensure upper string can be pick up urgently when the string stuck in the well.  Feature  • Simple,Website:http://www.dhpetrotools.com, easy operate;  • Apply pressure and pull the string to release, reliable;  • With pressure relief reveal to prove release.  ParameterMax OD.(in)Min ID.(in)Ball Dia.(in)Length(in)Temp(℉)Pressure(psi)Thread(in)3.941.771.9718.43300100002-7/8 EU4.332.052.1717.91300100002-7/8 EU5.312.562.6818.31300100003-1/2 EU