heel hold down device comprises a base plate 2 adapted to be secured to the top surface of the corresponding ski the longitudinal edges of this base plate 2 are provided with four outwardly projecting ears 3 each having a central hole 4 adapted to be engaged by a fastening screw 1 the retaining device according to this invention comprises in this example four retaining supports each designated in the drawings by the general reference numeral 5 as shown more particularly in fig3 each retaining support comprises an inner washer 6 adapted to fit round the stem of the relevant screw 1 and an external body 7 forming an integral part of said washer the complete device consisting of molded resilient plastic material of suitable grade and composition the external body 7 comprises a pair of lateral depending legs 8 adapted to facilitate the keeping in position of this retaining support on one of the ears 3 of base plate 2 of the heel hold down device t for this purpose the distance between the legs 8 corresponds to the width of ears 3 besides the legs 8 project downwards beyond the level of washer 6 so as to engage the side walls of the corresponding ear 3 a retaining in turned ledge 9 being provided on the lower end of each leg 8 thus each retaining support 5 is adapted to be secured by snap or clamping engagement to.