square washer 24 can be placed over the threaded rod 22 washer 22 can be moved freely over the rod 22 a rubber plug 26 is placed over the threaded rod 22 and pushed up so as to tightly engage the washer 24 next a square nut 28 is screwed onto the threaded rod up to the rubber plug 26 lastly a cotter pin 29 is installed through a hole located at the end of the threaded rod to keep the assembly from coming off the end of the threaded rod 22 when the mount is assembled the threaded rod 22 with the previously assembled components is inserted into the tube 18 that is mounted to the stationary mounting surface 1 guide members 30 are mounted on surface 1 for being positioned in slots 32 formed in the movable extension 2 this allows for a smooth linear range of adjustment of extension 2 with respect to mounting surface 1 once the movable extension in the form of movable mounting surface 2 is positioned in the correct location to hold the computer or other object that is to be used by the end user the wing portion of the lock 20 is turned clockwise this clockwise rotation will turn the threaded rod 22.