White "Derail" sign plate made out of aluminum with an 18-inch diameter. The moon sign is three times as large as the usual blue derail sign. White retro-reflective white facing and oversized "DERAIL" lettering on both sides mean the moon sign can be seen at a greater distance night or day than the usual small blue derail sign. Moon sign plate fits any Aldon derail sign holder, hinged or portable. Product of Aldon® Company.