12 Pcs Drill Stop Bit Limit Ring, 3-16 mm Drill Bit Depth Stop Collars with Hex Wrench, Stainless Steel Silver Spacing Ring Positioner Locator, Adjustable Drill Positioner for Woodworking

Needed for very precise drilling into a kind of fibre board of low quality. Making a mistake was not an option. These depth stop items arrived and all was well. Easy to fit to the appropriate stop to the appropriate drill bit and, as my dear father used to say,"Bob`s your uncle". Job done. Yes, to me theitems worked perfectly. I suspect that professionals would would criticise the quality of their manufacturing,but I'm sure they will out live me, but more to the point, I can boast to my know-all grandchildren that there are hidden depths secreted in my brain with information of great consequence that these modest pieces of engineering will solve their singular problem if only they can find them in the garage !!!!!O God what am I still writing this for? Wheres the bloody wine? Sorry about the diatribe-been a busy day!