Left Wheel Thru is the same but in the other direction. Everybody turns to the left. The belles (dancers on the right) from each couple pass left shoulders with each other.

Wheel Thru is very commonly done from a squared set, at the beginning of a sequence. In this case, the dancers must start by walking forward, before doing the rest of the action. They will end up facing the other couples, just as with a Lead Right in the same situation. For example, after a Heads Wheel Thru, the head couples will be in the center facing the side couples.