The HO series was named because the tube is roll formed and therefore permanently closed, making these springs non-repairable.

HO series springs are available with Ø12, Ø15, and Ø19 mm tube diameters and with stroke lengths up to 125 mm. There are 4 color-coded models, all with preset forces. An adjustable model (black) is also available. It can be ordered either set to a specific charge pressure or it can be adjusted by customers with the appropriate charging equipment and training.