I recently installed a 12ft-lb V-Glide in my HW97. I ordered it directly from V-Mach in England. The cylinder and piston are beautiful and have a quicker shot cycle than the stock piston. My rifle is now much more repeatable with a small standard deviation and extreme spread, and this results in better accuracy in WFTF. I think you'll find that with the recent strength of the dollar, that you can order a kit directly from V-Mach for less than $400, although you will wait a couple of months while they build it. Well worth the investment IMO.