Sizes and coatings are available upon your request. You could send us your specifications or drawings. We will be happy to return a quotation ASAP as the average response time is within 24 hours. Meanwhile our optical designers are always available to assist with your special needs, and our factories in China are ready to meet your quantity requirements. Plano-concave (PCV) lenses have one flat and one inward curved surface. PCV lenses have a negative focal length and are used for image reduction or to spread light. Specifications: 1) Material: as requested 2) Diameter: as requested 3) Surface quality: up to 60 - 40 scratch and dig, or as requested 4) Surface accuracy: up to λ/4, or as requested 5) Centering tolerance: 3 arc minutes, or as requested 6) Diameter tolerance: +0.0/-(0.1 - 0.2)mm (depends on dimension) 7) Clear aperture: >80% 8) Focal length tolerance: ±2% 9) Bevel: (0.25 - 1.0mm) x 45º (depends on diameter) 10) Coating: as requested