Generally
A refurbished original oil pump strainer with new or refurbished mesh filter.
The strainer is filled with air, which makes it float and suck the oil as high up into the trough as possible, if the oil level in the trough drops, the strainer follows the level down so it doesn't suck air. With today's quality of motor oils, it probably doesn't matter, but with the oils that were available when the car was new, this was a good invention.
