Not seen SBC versions before!

It came about because the early GU5.3 lamps were held in place only by the pins and after a few lamp changes, because of the high current the lamps draw (especially the 50w lamps) the sockets would not grip the lamps properly and they would sometimes either drop out or weld themselves into the socket. These SBC lamps were an attempt to rectify that problem but it doesn't seem to have caught on and the problems were solved by having grooves cut into the neck of the lamp for a clip to grip onto which can be seen on the lamp pictured on the box, which is what I thought I was getting lol.

Interesting...Thanks for the info