Designed by us and made for us by PWR in Indianapolis, these oil coolers were carefully thought out, designed and heavily tested.  It's designed to be a direct replacement for the Carrera coolers ('84-'89), or the generation cars with the so-called trombone cooler, as well as the earlier cars that didn't have any oil cooler at all.  They are designed to be used with the OE oil steel tubing (hard lines that run along side the car and up into the front right wheelwell), along with two OE flex holes used on the Carreras, and the OE lower mounting bracket. 
The cooler is 67% larger than the "Carrera" cooler in total volume and has a temperature bung so a fan thermostat can be used - turning on and off the fan when the oil temperature exceeds 186F and also has a drain plug for easy cleaning if needed. Its lower mount design allows the OE Carrera lower cooler bracket to be used (though repositioned) along with two "lord" mounts (rubber vibration dampers with M8 studs on each side).  All parts are sold separately, please see photos and variants,
The louvered panel is sold separately (some people mount the coolers in different positions), though it is recommended for any fender installation as the factory used on their coolers - to protect them from gravel and other propelled objects.
A "push" fan is also available that mounts on its own front mounted bezel (both separately). Two fans can be used if the headlight bucket is removed or modified for specific purposes, but a singe fan can be used on any road-going car. On hot summer days here in California we have tested them in 106F ambient temp and in bumper to bumper traffic and the oil temp remained at 190F with the fan hooked to the provided thermostat bung (see pic) - it uses a standard Bosch radiator fan switch, switches on at ~186F (86C).