The ITT D38999/26JH21HN is a circular, high-density printed circuit board connector. It features a quick-lock coupling system and has a keying system to prevent mismating. The series has a high-performance contact system and is designed for a wide variety of applications, including aerospace, industrial and commercial. The connector is available in numerous styles, such as panel mount, board mount, and jam nut. Additionally, it provides up to 250 contact positions. The connector is hermetically sealed, making it suitable for severe operating environments.