The FP flow pencil similar to a fountain pen in that it flows the paint out the nib instead of spraying it. The FP is used extensively for pin striping, taxidermy, cake decorating, Special effects makeup, etc. No air source needed. Comes with 4 size nibs. Lay down fine line with no overspray. Does not use a compressor. Comes with 1/16, 1/32,1/64 and 3/64 size nibs. Optional ALP-45 pressure cup for thicker paints.