KIT - 24x36 sign plus each of 3 magnetic MARSEC level signs
MARSEC is the Coast Guard's warning system analogous to the US Homeland Security Advisory System (HSAS). 
Signs are 24" x 36", printed on White Reflective Vinyl and mounted on .080 Aluminum with 2 or 4 holes for mounting. 
The MRS500 is a kit that contains the 24" x 36'" sign plus one each of the three different magnetic MARSEC Level signs. 

Price per MARSEC Kit