Air Lift Fittings 21851 Air Lift Company has developed dependable air spring suspension products since our inception in 1949. All our efforts are spent ensuring your safety and comfort by designing, engineering and manufacturing the highest quality suspension products. Elbow Elbow; Male; 1/4 in. MNPT x 3/8 in. Tube; Air Lift Elbow- Male 1/4in Npt X 3/8in Tube