Model 61系列空气放大器常见型号有：
Models 61H   Models 61L   Models 61F  Models 61FE   Models 61VH

61系列升压继电器以1:1的比例复制的气动信号的应用中，输入隔离或增加的流量要求。

The series 61 Booster Relays reproduce pneumatic signals in a 1:1 ratio for applications where bbbbb isolation or increased flow capacity are required.

61vh是一种高容量升压继电器设计用于对控制阀等执行器，需要非常快的开关速度。无论是61H和61vh特征稳定的旁路针型阀的输入和输出之间，从而消除了对外部管道旁路的需要.

61VH is a High-Capacity Booster Relay designed for use on control valve actuators that require very fast stroking speeds. Both 61H and 61VH feature a stabilizing bypass needle valve between the bbbbb and output, which eliminates the need for an externally piped bypass.