ROBERTSON 3M10077 S28P /A mBallast, Fluorescent, Preheat Start, 28 Watt CFL, 1 Lamp, 120Vac., 60Hz., NPF Save 17% over the individually packed version by ordering our Quik-Pak of 10 ea. Individually packaged units: 2M10077 S28P /A Two Year Factory Warranty-ONLY if the Amazon Seller is ROBERTSON Worldwide. Take advantage of ROBERTSON's 60 years of electronic design and quality manufacturing experience