P311540 Prym Flexi buttons. Available in case the collar or waist size varies. Thanks to their flexible spring steel loop, they are fastened to the regular button and can then be conveniently closed with the button hole. These are available in assorted sizes of 10, 15, and 19 mm or in 3 units each in sizes 15 mm, and 19 mm. 311540 10/15/19mm 3pc