20mm = .79"
5/120 bolt pattern; 72.5 center bore
DRA type = spacer fits in between the wheel and the hub. The spacer is bolted to the hub with special bolts (included). Your wheel bolts to the spacer.
Hubcentric = Yes, this spacer comes with a new hubcentric lip for the wheel to rest on.
H&R's 20mm wheel spacers are Made in Germany and are TUV approved. H&R manufacturers their spacers from a super lightweight aluminum/magnesium alloy for excellent strength and also to save unsprung weight. The spacers are drilled for additional lightness and easy fitment. They are then hard anodized for durability. These are not low quality universal spacers - the bolt pattern, hub sizing, and other dimensions are designed to be used on BMW models only.
This spacer is the bolt-on style - it is bolted to the hub using special mounting bolts. Your wheel then bolts to the spacer just like the original hub.