pitch of the threads of the threaded internal surface 426 approximately 0 125 0 500 inch more preferably 0 20 0 30 inch and most preferably 0 25 inch and preferably allow for 0 25 inch of length adjustment per turn of the actuator screw 60 within the grip sleeve 40 body 420 as shown in fig5 the o ring 90 sits within the first cavity 625 and abuts the flange 640 cushioning the head 72 of the screw 70 when the threaded extension 74 is fully threaded through the through bore 645 as shown in fig8 d and 8e the first cavity 625 of the actuator screw 60 has a hexagonal internal geometry 626 which is sized to mate with a hex wrench not shown white the second cavity 635 has a cylindrical internal geometry sized to receive the tip portion 230 of the shaft adapter 20 as shown in fig5 the through bore 645 is located within the actuator screw 60 to line up with the threaded bore 235 in the tip portion 230 of the shaft adapter 20 when the tip portion 230 is disposed within the second cavity 635 in alternate embodiments the first cavity 625 may have any type of structural configuration that receives a wrench or other tool having mating geometry in the preferred embodiment the o ring 90 and the screw 70 are inserted into the first cavity 625 of.