... Widely Used Backlit LED Letter Sign: 1MaterialFront and sides: High grade stainless steel, no rust and long lastingBack: Acylic(PMMA) ... of signs including letter signs, LED signs, LED channel letters, metal letters, acrylic letters, traffic sign, road sign, safety sign ... , signboard, exit sign, metal sign, lightbox, pylon, stainless steel letter sign and golden letter ...