RSVP 1031 model numbers are easy to understand.

For example, MODEL NO. 26051SR080C1000C

    26     Indicates the size of the body and torque plug
    05     Indicates pressure cylinder diameter
    1       Indicates the number of pressure cylinders
    SR     Indicates a spring return model
    080    Indicates spring rating
    C       Indicates failure mode
    1       Indicates internal soft seal’s material
    0        Indicates override type
    00     Indicates special requirements
    C       Indicates cylinder material