Into Gear's premium range of motorcycle battery maintaining and charging units come from the best in the business, Optimate. 
The complete adapter kit for SAE to DC2.5mm
Includes everything you need to transform SAE to DC2.5mm and vice versa – SAE to DC2.5mm socket, plug or SAE to SAE: Polarity Adapter, SAE – DC Socket and Plug Adapter.
O-67 KIT includes 3 separate cable adapters:
O-67M adapter, SAE to 2.5mm jack/plug
O-67F adapter, SAE to 2.5mm socket
O-27, SAE to SAE polarity adapter
Tech stuff:
16AWG / 0.52mm 5A / 7A Max Cable 
Thicker SPT-2W Insulation
Plug-SAE Connections