The retrofit C9-V2 has a thicker shell. It can be identified from the V1 by the absence of a ring on the plastic where the bulb meets the base. Commercial-grade LED Replacement Bulbs are long-lasting, unbreakable & IP65 waterproof. They save energy, are cool-to-the-touch & dimmable. Our design is PATENTED, (c)UL listed and Prop 65 certified to have no components known to cause cancer by the state of California.