GDC Double End Probes Thin William / Screening Probe # 6 (PCPQOW/11.5B) GDC has an advanced R&D department, as well as specialists who understand how the instruments must perform in surgery. Every year, instruments are updated and redesigned where ever necessary, in cooperation with the expert opinion from all their worthy buyers and knowledgeable customers, helping them to regularly revolutionize their products to the best of the ailing humanity. GDC uses the finest material, the best grade of stainless steel, depending upon the type of instruments; various quality checks are made starting from the forging to the final approval by the quality control department.