PRO 49mm Filter Kit + PRO 49 mm Tulip Lens Hood for Canon EF 50mm f/1.8 STM - 49 mm Polarizing Filter, 49mm UV Filter, 49mm Florescent Filter & 49mm Flower Lens Shade Hood Filter Kit: 49mm Circular Polarizer (rotational), 49mm Ultraviolet Filter, 49mm Florescent Daylight Filter - HD Multi-Coated Low Dispersion Optical Glass - Aluminum Ring Fitted 49 mm Circular (Rotational) Tulip Lens Hood, Flower Lens Shade Fits Perfectly On To Lens - No Adapters Required Look at your lens for the symbol  usually on the front or under the lens cap (under the cap will just be a number) the number next to it is the filter thread size.