TT Motorsports Sping Loaded Premium Mushroom Handle Pull Pin ,1" diameter x 1.5" Long steel weld on barrel with Set Screw to prevent pin from coming Loose 1 3/4" Diameter Handle.   1/2" or 3/8" Diameter pin
 
Used in Quick release mounts for jack skids, fire exstinguisher mounts, seat sliders, sun visors. etc.