1.flat back with 2 holes 2.High quality 3.No lead,no nickel 4.other color can be customized One -Stop button Manufacturer We ... 3.Available in various designs and color 4.Nickel free and lead free,low cadmium 5.High quality,pretty competitive price,satisfactory ... :Offset,Screen printing,coloring,laser,embossing,etc . up to you. Color card to match: Other pattern acrylic stone to choose : Payment ...