Just what I was looking for
These are great. They seem to be very durable, and look like they will stand up to outside usage well. The black plastic around the base of the bulb provides a good seal. At first when I put the bulb in and plugged it in, it didn't come on, and I was thinking it was defective. However, after looking, the plastic at the base of the bulb is soft enough that if you just continue to screw the bulb in, past where it stops, the plastic stretches around the base of the bulb, and you can thread it the rest of the way in and it makes a nice snug seal. It's a tight fit, but it will go. I appreciate the good seal, that is exactly what I was hoping for.
Prosgood seal, well constructed