Genuine Reichert Ocu-Film tip covers are the only tono tip covers approved for use with TonoPen tonometers. Ocu-Film+ tip covers protect your Tono-Pen from dust fluids, and help protect patients from cross contamination. These Reichert tono-tip covers, product code 23-0653, are sanitized and packaged in a bulk pack of 600, but are not individually wrapped.Please Note: FDA approved Reichert Ocu-Film+ tip covers are blue in color to assure the user that the tip cover is the genuine brand approved for use with Tono-Pen AVIA and Tono-Pen XL tonometers. Using non-Reichert tono tip covers could cause damage to your Tono-Pen and void the warranty, as well as necessitating expensive transducer repairs. Non-Reichert tip covers could also potentially cause the Tono-Pen to give erratic readings. Protect your Tono-Pen and your patients by using only blue Reichert Ocu-Film+ tip covers.