Columbia Lighting Back-Lit Troffer, 120 to 277 V, 29.25/39/50 W Fixture, LED Lamp, 120/127/133 Lumens/W Light Output, 60000 hr Average Life, 4000 K Color Temperature, 80 CRI, Acrylic/Frosted Lens, 3300/4400/5500 Lumens, Ceiling/Surface Mounting, Aluminum Frame/Steel Housing Material, 47.76 L in x 23.74 in W x 1.72 in H Dimensions