Remote filter heads are designed to relocate the engine oil filter due to lack of space in the original position. This makes them useful for engine conversions or other modifications which limit space.
This Mocal remote filter head allows an 80mm or 98 mm diameter oil filter with a 3/4 UNF thread to be fitted. A range of suitable oil filters can be found HERE.
The inlet and outlet ports are both positioned on top of the housing and have a female 1/2 NPTF thread