Designed for vertical ID cards with a slot to fit a lanyard through. Also has an insert for an RSA SecurID device on the backside of the ID holder. Just slide in the ID and RSA key. It is a tight fit so they don't slip out. Fits standard ID size: 85.6mm x 53.98mmRecommend scaling up the size of the piece by about 1 - 2%.Print the thing vertically standing up.Tested on Printrbot Simple Metal with Repetier & Slic3r: Clear PLA filament @ 185 C, no heated bed. Black PLA filament @ 195 C, heated bed (60C). Print model scaled up by 2% in Repetier. Layer size 0.15mm, no supports, no brim, no raft, default speed.