3 Series 3010-D, glow-in-the-dark/ultra reflective letter-D, these highly visible markers are ideal for clearly identifying electrical utility equipment such as electrical boxes, pedestals, transformers and utility poles. The numbers and letters are also optimal for facility identification and general purpose marking such as aisles, equipment, shelving and bins. Legend is "D", size is 3-1/2" Height, 2-1/2" Width, character height is 3", color is black, glow-in-the-dark border/silver, material is high intensity prismatic reflective sheeting and photoluminescent material with a pressure sensitive adhesive. Illumination characteristics are illumination - 21.6 lux (2 foot-candles) for 2 hours with a 4100K cool white fluorescent lamp. Luminance (after illumination) is 10 minutes >29 mcd/m2, 60 minutes >7 mcd/m2, 90 minutes >5 mcd/m2, 120 minutes >3 mcd/m2. Adhesive type is pressure sensitive acrylic. Substrate type is reflective sheeting. Standard material color is silver, standard legend color is black with photoluminescent border. Relevant standards is exceeds application requirements of type III & IV per ASTM - D 4956. Adhesive Properties are adhesion to steel (PSTC-1), 15 minute dwell (Average) - destroys, ultimate dwell (72 hours) (Average) - destroys. Abrasion resistance (method 5306 of U.S. Federal test method std. no. 191A) is CS 17 wheels, 1000 gram weight, legend withstands 334 cycles. Gloss (ASTM D523) is 60 degree Celsius gloss on reflective area - 92 gardner gloss units. Average outdoor durability is up to 12 years outdoors (average expected outdoor life of product will depend on user definition of failure and climatic conditions).