Designed for countless metal marking applications. Can be used for marking greasy, rusty, or new metal surfaces Also suitable for marking glass, plastic, wood, ceramics etc. Ballpoint nozzle cap will only allow ink flow when applied and pressed to the workpiece - ink cannot be spilt from the cap unintentionally. One head can be interchanged from differing inks and bottles. Can be refilled from 1 litre bulk refills of the specially formulated ink.