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. Minleon’s commercial-grade LED Replacement Bulbs are long lasting, unbreakable and IP65 waterproof. They save energy, are cool to the touch and dimmable. Our design is Patented, ©UL listed and Prop 65 certified to have no components known to cause cancer by the state of California.