The Kodaslide projector was a side-loaded projector - meaning a new slide was loaded when you pushed out the old one (the original model had a top-load feature).  This projector's manufacture coincided with the !st Kodachrome Kodaslide Ready-mounts which were also introduced in 1939. It was the most compact projector of its time. It originally sold for $18.50 and the case sold for $4.00 (it was known as the "Projecto" case).