Wheel bolt sizes

[Deeps]

Does anyone have an idea what wheel bolt sizes Mazda use on their 17" wheels as fitted to my CX-5? In the image the bolts look 'gold' but that's a trick of the light LOL - they are in fact standard steel items.
I own a 17mm adapter for use on my torque wrench when checking the bolt tightness of the caravan wheels and a 19mm adapter for checking the bolts on the winter alloy wheels on the CX-5. Silly me thought that the bolts would be the same on the summer alloy wheels now fitted but no, they are even bigger.  Before I go rushing out buying yet another adapter does anyone know the correct size?

Edit: Unbelievably upon calling Mazda HQ here in Germany they were unable to tell me the size of bolts fitted to the CX-5 (17" wheels) although they were able to confirm that the torque should be set to 120NM.

Update: I wanted to get on with this job so took a short walk to my Mazda handler. For reference purposes and for possible useful info for members at a later time, the adapter/key required for the standard Mazda wheel bolts is 21mm whilst for special order winter alloys which come with their own and different size bolts, a 19mm adapter/key is required.

[RichardCX5]

I see you've answered your own question! For anyone looking for information, the wheel bolts on the 19 inch wheels (as fitted to Sport aka top-of-the-range models) are also 21mm.

P.S. Deeps, where are your locking wheel bolts nuts?! (Edited for you xtrailman, I guess I should have known that myself since I was taking my wheels off today!)

[xtrailman]

Locking wheel nuts, the cx-5 does not use bolts, or fitted by the dealer in the UK, so not standard in all markets.

Which is why i have 8 spare nuts, from two cx-5.

[Deeps]

You've both lost me a bit with this 'nuts and bolts' saga  but as long as you both do that's ok. Never actually found a need for either locking nuts or bolts as the sort of driving that I do nowadays - or perhaps more to the point - places that I park up the car, don't call for the extra expense (he says touching wood). It could also be a case of that over here in the south we don't have the number of thieving toe-rags that you seems to have.