This set of 2 Master Mechanic 239140 plugs with 3/8 inch diameter and 1/4 inch MNPT connection is a great deal you don't want to miss! Made for hydraulics, pneumatics, pumps, and plumbing industries, these fittings are versatile and reliable. The brand Master Mechanic is known for its quality and durability, making these plugs a must-have in any professional's toolkit.