... Consists of injection needle, barrel, plunge, piston, elastic clip, positionfixing board, resistant ring and resistant plate2) Technical requirements: a) Using method is ... Resistant force for puncturing rubber piston, pull off force and plunger broken force are complied with the standard of Q ... be drawn back into barrel after single use, safety and guarantee for single use Packing: 1pc/bag, 100pcs/box ...