Reflector Mounting Style Screws Bolts or Rivets Round Red Overall Width 3/4 in Overall Length 4 11/16 in Overall Diameter 3 5/8 in Federal Motor Vehicle Safety Standards Met SAE A Housing Material Steel Mounting Hardware Included Yes Mounting Hole Diameter 3 15/16 in Number of Mounting Holes 2 Permanence Removable Reflector Material Acrylic Standards FMVSS SAE A