The APR Drill Stem Testing Tools is the Full bore Annular pressure Operated DST tools, which is used for the well testing, including RTTS PACKER, RTTS circulating valve, DST Tester valve, OMNI valve, Hydraulic jar, Big John jar, DST Sampler, Drain valve, CHAMP PACKER, ZZ TOP is the DST manufacture and with professional technical team , we are able to provide training at the factory and oilfield work site.