thin green line..

..marking the 'runway' of the black bed.
Intersecting with another green laser line at right angles the two are used to get the bod into the correct position referencing the tattoos on my lower back.

Lowering onto the bed is a bit like landing a plane and after 12 sessions now I'm apparently 'landing very well' with not much shunting and bed clicking needed to be in the perfect position.

Wheels up!!