... very tiny(diameter of globe is only 0.5M); the total weight is light(alumimum sphere ... . 2 years replacement warranty. DIAφ0.5m,φ1.0m,φ1.5m,φ2.0m,φ3.0mOther sizes can be ... pure barium sulfateParameterReflectance p≈0.8, variation of ρ(λ)<1.5% in the visible range.AdvantageThe reflectivity curve ... more accurate than normal 0.5cm ,1m,1.2m.1.5m.2m diameter Lumen tester sphere,different diameter and functions ...