thereof and a u shaped protuberance or projection 28 disposed at the other end thereof the forewardly facing hook means 27 is comprised of a vertical portion 30 extending upwardly from the top surface 32 of said lower member 14 and a horizontal portion 34 substantially parallel to said top surface 32 as shown in fig1 and 3 the lower member 14 is disposed beneath said upper member 12 it is positioned so that said forwardly facing hook means is in registration with the aperature 16 and the u shaped protuberance 28 is in registration with aperature 18 as shown when said lower member 14 and said upper member 12 are in registration as described above the hook means 20 and 26 form clamping means which will be further described below and the u shaped protuberance 28 in association with the top surface 22 of the upper member 12 forms a transversely disposed aperature 35 which will also be further described below with reference primarily to fig3 the use of the security device of the present invention will be explained a business machine m such as a computer or typewriter is usually supported above a work surface s by legs not shown most such machines are provided with an aperature 36 in the bottom surface 38 for various purposes as shown the security device 10 of the present invention is located below said bottom surface 38 of the machine m in the space between the machine m and the work surface s as further shown the clamping means comprising the forward facing hook means 27 of the lower member 14.