The Proviz Switch Vest is made from a dual-layer outer shell that can be worn either way to give you two options, one for the day and one for night. By day, the fluorescent yellow material enables customers to stand out and be clearly seen. By night the reflective material lights up when vehicle headlights are shined upon it enabling the user to be seen more clearly on the roads, therefore enabling drivers to adapt accordingly to your position on the road. About the fabrics: The fabrics used for the Switch range were chosen specifically to make the Switch Vest extremely versatile. The reflective material used is the same as the incredibly popular REFLECT360 range and it is certified to CE EN 20471 standard. Reversible: Light Blue / 100% reflective (CE EN 20471 certified) | Two-way reversible zipper | Meshed reflective material to aid breathability | Chest pocket | Back pocket | Zip pulls | Machine washable | Colour: Yellow, Blue, Black | Size: UK 06 / US 2 / EUR 34, UK 08 / US 4 / EUR 36, UK 10 / US 6 / EUR 38, UK 12 / US 8 / EUR 40, UK 14 / US 10 / EUR 42, UK 16 / US 12 / EUR 44, UK 18 / US 14 / EUR 46, UK 20 / US 16 / EUR 48, UK 22 / US 18 / EUR 50, 22, 20