Each sphere is made from lightweight cotton material. There is a central hole located in the base of each. Hot glue can be used to firmly secure a floral wire inside. (Available in 7 graduating sizes) Cotton Sphere (4) Set of 12 - 1.7cm (H) x 1.7cm (W) - (3.4" x 3/4" W) The larger (Sphere 1) is perfect for attaching unwired petals to creating a lightweight large bloom such as Peonies and closed ornamental cabbage. The medium/small sized spheres (Sphere 2,3,4,5,6,7) can be used for a wide variety of closed peony, poppy buds, blackberry buds, and pom pom dahlia flower centres. Robert designed these spheres with the following benefits in mind. Speed – You can cover various sphere sizes in paste, simply texture or add as little as 5 cupped petals for an opening peony bud. These spheres will save on time limiting the number of inner petals used for larger unwired blooms. Space substitute – Use to fill cavity moulds for example – making lemon or blackberry fruit, lotus flower centre & lotus closed buds lighter. (Simply fill each cavity mould sparingly with paste and sandwich the 2-part mould around a wired sphere). Extremely lightweight – perfect for arranging numerous finished peonies, roses and closed flower buds for safe/stable cake designs. Tip - If fully immersing a finished unwired sugar peony, rose etc, into Robert’s matt or satin setting glaze, please ensure the whole sphere is airtight and completely sealed in paste before applying petals. (leaving no exposed areas of the cotton sphere showing)