4" ENGINEERING GRADE SAFETY REFLECTIVE TAPE - in 7 solid colors, conforms to the requirements of ASTM D 4956, TYPE I reflective sheeting (call for Type II).  This thin (5.5 mil) retro-reflective tape has a peel-off backing and permanent acrylic adhesive.  It utilizes embedded microscopic glass beadlets to reflect light and is used on firetrucks and postal service vehicles.  It makes flashy reflective striping on cars and boats and is also great for reflective markings on bicycles, helmets, gates and signs.  It meets federal specification LS-300C (Engineering Grade) for reflectivity, longevity (7-year minimum), and resistance to weathering (should be applied at a temperature over 50ºF, but is service rated from -40ºF to 180ºF).  The brightest reflecting color is white, followed by yellow, then orange, red, violet, 3M black, green, and blue.  Tape is sold in 15-foot increments and 50-yd rolls.