SMQ_250_ATP is a snap in fresnel square lens in amber color. LED size is 3mm (T-1) with lens height of 0.290". It mounts in a 0.171” (4.34mm) square punched hole on 0.250” (6.35mm) centers with a panel thickness of 0.031” (0.8mm) to 0.094” (2.39mm). Easy assembly – insert lens through panel hole and insert LED into lens.