Original BookArc was a silver metal stand with numbers (1-8) embossed on the inserts.
BookArc Möd was a wooden stand with numbers (1-8) embossed on the inserts
BookArc for MacBook Air was a silver metal stand with "1A" embossed on the insert.
Current BookArc* is a metal stand, available in silver or space gray, and has letters embossed on the inserts (A-I).
*Replacement inserts are only available for the current version of BookArc for MacBook.