BRITE MARK® 40 Threaded Cap Barrel Permanent Paint Marker, Valve Action, Red, Medium no checkout Features a one piece dual hex nut Features a one piece dual hex nut that eliminates interference issues and simplifies periodic flipping of the wheel for maximum cutting action MRI non magnetic ball pein hammer helps protect employees and MRI equipment during maintenance and repair work For use in locations where flammable or combustible vapors or losing opacity Valve action mechanism prevents paint in barrel from drying when cap is left off Bullet tips are replaceable to assure complete use of paint in each marker Heavy duty aluminum body with large paint capacity oil based paint withstands indoor and outdoor conditions without fading