WolfcraftInternal Dimension Adapter for Folding Rules I 5223000 I For taking internal measurements using a folding rule

This solves a problem I have always had. Internal dimensions.Instead of bending a tape and trying to squint and guess what is the true measurement. This give you the exact measurement.Easy to use, no idea what rules others are using but it fits the normal folding rule that common now.I guess they are still using the old four fold boxwood rules, which is doesn't fit.Worth every penny, not just for the time is saves but that lovely feeling when you cut something and it fits beautifully.

Makes measuring internal spaces easier

This is one of those simple solutions that your surprised more people don't sell. Truth be told you can get a similar effect with bulldog clips and cardboard, but this is a lot sturdier and easy to store.Essentially the way it works is you put your folding rule into the internal space that you are trying to measure, folded to the nearest segment that fits, you then slide this along to fill the gap, remove the whole lot from the gap, straighten the rule and read off the end of the gauge against the rule. This gives the correct measurement.It's actually a lot easier to do than my description makes it sound!Only difficulty is down to the fact the gauge does not lie flush on the rule and therefore you only really get an accurate measurement if you look down on it dead straight. I've attached three images of the same measurement but viewed from different angles and you can see the potential for error here. The effect is magnified if you fold out the extension piece which will be dependent on how far a gap you want to fill.Ultimately, used carefully it allows you to more accurately measure internal spaces than say bending the tip of a retractable tape. I've used it with rulers made by multiple manufacturers without any issues. Also takes up next to no room in your bag and isn't badly priced (although if it was any more, I'd be reaching for the bulldog clips)

Folding rules can have one drawback, measuring internal distances in, for example, cabinets or boxes, or window openings. You can measure edge to edge, but if you measure inside you end up with a tape measure bent in a curve and a guess, or with a folding rule it is always too short or long - if the extended rule just fits, then it's time to buy a lottery ticket with that sort of luck.In the real world the distance will be somewhere between extensions. Use this adaptor and the problem is solved.You fix it to the far end of the rule, extend it to the inside edge of the cabinet or whatever you are measuring, lock it, remove the rule and fold out the rest of the rule which slides under the adaptor and where the adaptor ends on the new rule length is the exact, accurate measure. It sounds a bit complicated, but the video on the Amazon product page explains it, and nothing could be simpler to use. It is a cheap item, probably not in daily use by the average DIY enthusiast, but still one for the toolbox and invaluable when needed.

If you have the matching folding ruler, these are great for measuring across a gap

Got for a job I need to do and part is missing absolute crap who picks and packs these

This is a simple tool made from decent materials that does not cost a fortune. If you have a folding rule this will come in very handy when you need to measure internal dimensions, in fact this tool makes a folding rule far more accurate than a steel tape for measuring internals.Oh and just for good measure, (pun intended), it's well made and inexpensive.

Got this with folding ruler for son to measure stair widths & recesses for laying carpet & laminate. Makes life easier