12V Single phase regulator / rectifier unit & plug kit, has separate negative wire and isolated from casing, so can be used for + or - chassis, see pictures for typical circuit. 

4 x 6.3mm male spade connectors in multiplug

max. 15A input (180W )

Max. charging current 4A

Charging voltage 14.5 (+ or - 0.5v)

two yellow ac inputs from alternator

red +ve is fused to battery

green -ve is chassis negative

measures approx. 70mm x 59mm x 24mm

fixing holes are 56mm centres but are oval giving a couple of mm of extra clearance.