and its body 61 has major and minor wings 67 and 68 respectfully which can be respectively positioned adjacent to the lower wings 37 and 38 of the cannula handle the body 61 has a curved seating projection 62 having a complementary dimension to fit into and mate with seat 40 projection 62 defines a central cylindrical chamber 64 which can receive the luer lock 20 of the lower gripping handle 32 the portions of the underside surface of the body 61 on opposite sides of projection 62 have a planar surface 65 allowing it to set flush against planar surface 41 of the corresponding structure of the lower cannula handle section 32 the major wing portion 67 of the body defines locking nipple 66 which fits in locking depression 42 on the upper planar surface of the lower cannula handle 32 to keep the two handle sections in a fixed relationship when the device is being used two parallel locking pins or rods 70 are mounted to the curved projection 62 on opposite sides of the cylindrical chamber 64 the parallel orientation of the rods 70 allows insertion of the same over the luer lock 20 and rotation of the body 61 90 u00b0 degrees to lock the handle assembly 30 in place with the respective major and minor wing portions of the two handle sections 32 and 60 being positioned adjacent each other the stylet can be removed by twisting the stylet handle section 60 in relation to the lower cannula handle section 32 to disengage the rods 70 from the luer lock 20 allowing the stylet to be removed from the cannula 12 and a standard syringe not shown to be attached to the luer lock 20 for the purpose of withdrawing bone marrow an alternate.