Most of us stick our bikes on charge when not in use.
Optimate leads etc normally share the same connector
one contact is square
and the other half square/half round
This little gizmo fits into your pocket and plugs directly into your optimate/oxford tail lead...... then you plug your phone into it!
Going touring? or out for the day? Nothing worse than a flat phone battery...well, you can forget all about that now !

Im selling them at £6 a piece...pm for further info