Special aviation aluminum alloy, high strength, impact resistance, twist and pressure. Machining process.
Surface treatment: high-mesh sand blasting machine and color quality pure matte black or silver. Ultra-low chemical residues, attached to a solid!
Font Handling: Font clear mission, silk screening of non-mimeo, attached to a solid!

Package Included:

37mm-49mm Step-up ring x 1 
49mm-52mm Step-up ring x 1
52mm-55mm Step-up ring x 1
55mm-58mm Step-up ring x 1
58MM-62mm Step-up ring x 1
62mm-67mm Step-up ring x 1
67mm-72mm Step-up ring x 1
72mm-77mm Step-up ring x 1
77mm-82mm Step-up ring x 1

(all 9pcs)
Using Step Up And Step Down Rings To Take Better Pictures