Rinzl Disposable Plastic Microscope Coverslips. Made of unbreakable, clear vinyl plastic. Refractive index as glass. Use in biological, medical and educational labs. Excellent for veterinary field work. 22mm x 22mm square, 0.17mm thickness. Each individual paperboard box contains 100 cover slips. There are 10 boxes per Master Pack totaling 1000 cover slips. Made in America.