The Original Little Foot Quarter-Inch Presser Foot by Lynn Graves.  This foot is clear for greater visibility.
 
The right edge is 1/4" from the center needle position which gives you a scant 1/4" seam allowance.
The left edge is a scant 3/8" from the center needle position.  This gives a better tension control, as it will cover more feed dogs on most machines.