The present invention relates to a coupling device (100) for connecting a residual limb liner (10) to a residual limb socket (20) of a limb prosthesis, characterized by: a magnet assembly (120) comprising a permanent magnet (122) sandwiched by a pair of iron bars (124) for creating a magnetic field a housing (110) comprising a protrusion (112) for intensifying magnetic field and a cavity (114) for receiving the magnet assembly (120), wherein said housing (110) is embedded at a distal end of the residual limb socket (20) a controlling means (130) coupled to the housing (110) and the magnet assembly (120) for controlling the magnetic field by rotating the magnet assembly (120) and a mounting plate (140) coupled to the residual limb liner (10) wherein the mounting plate (140) is attracted to the protrusion (112) of the housing (110) when the permanent magnet (122) is vertically aligned, thereby attaching the residual limb liner (10) to the residual limb socket (20) and wherein the mounting plate (140) is repelled from the protrusion (112) of the housing (110) when the permanent magnet (122) is horizontally aligned, thereby detaching the residual limb liner (10) from the residual limb socket (20).
