Afco Double pass radiators gain their efficiency by first passing the fluid over the top half of the radiator and then the bottom half, giving the radiator the ability to dissipate heat twice. These use an exclusive 360 degree TIG-welded baffle that splits the radiator core into two sections. This 360 degree baffle effectively creates two radiators out of one and assures that you wont have any coolant that has entered the radiator but never made it across the core. This is superior to utilizing silicone to seal internal baffles, or worse, a partial weld that allows the coolant to bypass the radiator core completely.