Made from EPDM rubber Multiplicity of uses Non-toxic Pack of 13 set contains: 3 X 6mm x 3mm 2 X 7mm x 2mm 2 X 8mm x 2mm 2 X 9mm x 2mm 2 X 10mm x 2mm 2 X 12mm x 3mm Easi Plumb O Ring Kit 2 ( 13 X 6 - 12Mm ) | Epork2 The Easi Plumb O Ring Kit No. 2 contains 13 various sized EPDM rubber rings. These rings have multiple uses, are non-toxic and can be lubricated. This set contains: three 6mm x 3mm, two 7mm x 2mm, two 8mm x 2mm, two 9mm x 2mm, two 10mm x 2mm and two 12mm x 3mm.