From Radio-Mat Slide Co. in Daytona Beach, FL:  Two open packages of Radio-Mat Slides plus one glass slide.  Used in a typewriter to make glass slides.  


Each box measures  4.5" x 3.5" x 1".  There are directions for use on the back of the box.  

One box is stamped "amber"; the other box is stamped "white".  Box marked "amber" has 49 pieces for making glass slides; it weighs 4.1 ounces.  Box marked "white" has 15 pieces and 1 glass slide; weight of this box is 4.3 ounces.

Shipment by US Postal Service 1st Class mail..