This is a vintage two piece plastic drink coaster cover set with a time dial timer or clock face on the lid. The set was meant to be used with a glass of water or another drink. The glass would sit on the coaster and the lid would cover the glass. The patient would set the clock to the time they should take their next dose of medicine. Neither piece is marked. The coaster is 3 7/8" wide and the lid is 3" wide. Both pieces are in excellent condition. MBR.
Vintage Early Plastic Cream Clock Medicine Timer Drink Cover