Set of 2 track lighting sockets, Joint Lighting GT-GD-E26B The base size is E26. I installed them, but the black color didn't match, so I'm listing them here. The socket shape is close to a perfect circle, so it doesn't hit the edge of the track rail and fits in either direction. With the common shape, like a long oval that's been flattened, you can't insert it in the direction where it catches on the edge of the track rail, or it's very difficult to remove if you force it in. However, I think this product from Joint Lighting avoids that problem. The hinge bend is about 85 degrees. The seller, Joint Lighting's website says 90 degrees, but it's actually a little less than 90 degrees. The axis rotation angle is about 315 degrees (7/8 rotation). Used for less than 10 hours. # "Green" IT equipment/electrical products are here # "Green" interior related items are here # "Green" DIY related items are here