This is the RX Prescription Lenses for the Promate Scanner Mask Series - Optical Lens Features: Prescription mask available item code: MSK70 and MSK72 Please note there will be an additional 2 to 3 days processing time for most RX lenses Cost is per single lens only Ultra low volume Broad peripheral view Tempered glasses Optical lenses available from –1.0 to –10.0 by increments of 0.5 (for nearsighted/myopic) Optical lenses available from +1.0 to +4.5 by increments of 0.5 (for farsighted/hyperopic) Bifocal / Gauge Reader lenses available from +1.0 to +4.0 by increments of 0.5. (top plain without prescription, bottom with magnifier reader) RX Prescription Lenses for the Promate Scanner Mask Series - Optical Lens(Bi focal-Gauge Reader and Far Sighted). Returns are not accepted for used lens. Only unused lens are eligible for return with store credit.