Mine came from ebay and although I had never heard of this brand they are good quality and fitted perfectly.

They are hubcentric so have been machined for the back to locate on the spigot and, in turn, have another spigot on the face of the spacer for the wheel to centre on.

This is the best picture I can find but this listing is for a 5-stud car and is nothing to do with me. It's NOT the seller I bought from so can't say anything about them.
http://www.ebay.co.uk/itm/Hubcentric...item35a248b931