<prompt> Back action clasp is a modification of:Ring claspEmbrasure claspOnlay claspHairpin clasp  <response>: Back-action claspIt is a modification of the ring clasp.Here the minor connector is connected to the end of the clasp arm and the occlusal rest is left unsupported.Disadvantages:Lack of support to the occlusal rest reduces its function.It has both biological and mechanical unsound principles. 