... can be cutomized 9. 2 years replacement warranty. DIAφ0.5m,φ1.0m,φ1.5m,φ2.0m,φ3.0mOther sizes can be designed ... Sphere Paint coating inside adopts pure barium sulfateParameterReflectance p≈0.8, variation of ρ(λ)<1.5% in the visible range.AdvantageThe reflectivity curve ... than normal 0.5cm ,1m,1.2m.1.5m.2m diameter Lumen tester sphere,different diameter and functions for you. 0.5 1m 1.5m 2m ...