Natural rubber. These winding rubber bands, specifically designed for beauty professionals, are strong and durable. The rubber surface is treated with silicone, repelling cold perming solutions and minimizing stickiness. Winding / Rubber Bands / Beauty / Professional / Silicone Treatment / Beauty Salon / Professional Use The box will be flattened for shipping. Product Specifications Product Name: Flora Pro Beauty Band Boxed Perm Rubber Model Number: pro-beautyband-box Category: New ■ Material: Natural Rubber ■ Capacity: 100g (NET.) ■ Made in Japan ■ Rubber Size: Blue (#12: Folded Length 40mm / Diameter 25mm) * Folded Length: The total length of the rubber band when folded. * Diameter: The inner diameter when the rubber band is formed into a concentric circle.