Retaining Ring, Internal, 1/4 O.D., to fit A-dec® Century® II Needle Cartridge, Old Style Fits Century® II needle valve (old style) (A-dec® #010.017.00) Package of 10 A-dec® and Century® are a registered trademark of A-dec, Inc. DCI has no affiliation with A-dec and A-dec has not authorized DCI replacement parts to be used on or in connection with A-dec® products.