Tubing Connector Fittings, High Pressure, One Piece, 1/16", PEEK, Red, Large Combihead with 10-32 Screw Threads. Finger or wrench Tighten, ARE-Applied Research brand. Additional Info: These all PEEK "Male Nuts" are used to connect PEEK or Stainless Steel tubing in the high pressures zones of HPLC systems. This Combihead Fitting has a partially knurled, rounded head for hand tightening and a "Flat" section of the head for using a wrench for a final quarter turn or to loosen the nut when it is tightly screwed into the fitting. This fitting has 12mm head, 22mm total length (top to bottom) with an 8mm thread length. The beveled inlet hole helps to make threading the tubing through the fitting easier.