Idex Flanged Fitting, 5/16" Square, Black Acetal, 1/18" OD Tubing, 1/4-28 Flat-Bottom; 1/EA from Cole-Parmer Canada
Acetal/Delrin/POM/Nylon White Black Plastic Black Nylon Plain Washer DIN125 M8 M10 Nylon Black Plastic Shoulder Washer - China Nylon Washer Plastic, Colored Washers | Made-in-China.com