Feature:1. Can be attached to any bicycle to make colorful pictures when riding down the street, cruising in the lane or winding on the sidewalk.2. Fix it on the bike fixed frame to use, install the chalk, and then adjust the size, you can draw while riding.3. Comes with 4pcs of chalk of the package, which are durable and can bring endless fun.4. A very unique and novel idea. Wonderful and nice gifts for children and kids.5. Suitable for all sizes of bicycles and auxiliary wheels, suitable for both children girl or boy.Specification:Item Type: Bicycle Doodle PenMaterial: PVCBicycle Fixed Frame: BlackChalk: Random colorApplicable: Both male and femaleAge: No limitFixed Frame Height: Approx. 25.3cm / 10inFixed Frame Width: Approx. 3cm / 1.2inFixed Frame Tube Outer Diameter: Approx. 6.3cm / 2.48inFixed Frame Tube Inner Diameter: Approx. 4cm / 1.57inChalk Size: Approx. 11.2 x 3.5cm / 4.4 x 1.4in Package List:1 x Bicycle Fixed Frame4 x Chalk Note:Please allow 1‑2cm error due to manual measurement. Thanks for your understanding.