Not used one of those either, nice idea if nothing else. Bought the cheapest screwback tool off eBay, something like > http://www.ebay.com/itm/Wrench-Tool-All-One-Watch-Screwback-Case-Opener-/280835230797?pt=UK_Jewellery_Watches_Pocket_Watches_Accessories_ET&hash=item4163158c4d#ht_3085wt_1163 ...