From 2000 to 2012, all UK supplied OptiMates were fitted with TM (AKA “KET”) connectors. In 2012, the SAE connector was introduced. The easiest way to distinguish between the two is to look inside the rubber casing. The TM version has a white connector, while SAE versions are black. See picture below showing TM71 (early and late) and O1 (SAE71) connectors.
OptiMate Converter Leads
O7 - converter lead to connect a TM71 lead (fitted to a vehicle’s battery) to an SAE charger or accessory
O17 - converter lead to connect an O1 (SAE71) lead (fitted to a vehicle’s battery) to a TM charger or accessory