GE f32t8/xl/spx50hleco, 4', 32w, t8, 1" diameter, ecolux fluorescent bulb, medium bi-pin ends, 3,000 lumens, rated life: 36,000 hours @ 12 hours per start, color temperature: 5,000 kelvins, cri=80, higher lumens than standard 32w 4' bulbs, ease of disposal.