... front, fine welding Inner waterproof LED easy to install CE, UL certification Stainless steel led back light/halo letters for shop sign ... and front, no rust2. Fine welding3. Inner high quality waterproof LED (with CE/UL/RoHS certificate), over 50, 000 hours ... all kinds of signs including sign letter, LED signs, LED channel letters, metal letters, acrylic letters, traffic sign, road sign, safety sign, ...