I have 4 available, they are matched so if you need 2 or 4 I strongly advise buying them as a group. The Brimar CV493 6X4 CV4005 NOS NIB is a vintage rectifier tube with black plates, produced in the United Kingdom. This model has the brand Brimar, and is known as Cv493/6×4/cv4005/EZ90. This product would be a valuable addition to any collection of vintage audio and video equipment, offering a unique and authentic piece of electronics history.