Our Fluorescent Yellow Carpenter's Retractable Marking Crayon or Sumitsuke is oil free and can be used to mark any wet or dry surface, including wet paper, concrete, wood, metal, glass, tile and plastic. Sumitsuke are used extensively by carpenters, cabinetmakers, construction workers and gardeners. The fluorescent colors are great for use in dimly lit work areas. The 4mm (5/32˝) thick, spring loaded crayon is easy to adjust and retracts completely for storage. TheSumitsuke cap is color coded for ease of selection. Overall length is 5½˝.