Overview Reviews Product Description #4 O-ring Face Seal Cap. Made of Steel. Product Videos Custom Field Product Reviews Write a Review Write a Review × Parker Parker 4 Fnl-S #4 Fem Seal-Lok (Ffors) Cap Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *