O-VSG6574.ALCOHOL RETAINING WELL INSTRUMENTS.MATERIAL MEDICAL GRADE BIOCOMPATIBLE PLASTIC.CENTRAL RING PREFERRED FOR LASEK.HYGENIC AND DO NOT TRASNMIT ANY INFECTION.HOLD ALCOHOL IN THE RING CAVITY FOR PROTECTING THE CORNEA DURING LASIK / LASEK PROCEDURES.LIGHT WEIGHT & EASY TO USE.AVAILABLE IN 8.5/9.5MM.