It sounds like you're referring to a very specific type of SMA cable assembly with the following characteristics:br br SMA (M) St. – This indicates a Standard Male SMA connector. The "St." likely stands for "Straight" in this case, meaning it’s a straight connector with a male pin that would typically be attached to an RF device with a matching female connector.br br RP SMA (F) BH St. – This represents a Reverse Polarity SMA (Female) Bulkhead Straight connector.br br RP (Reverse Polarity) means that the typical pin-and-socket arrangement of the standard SMA connector is reversed. In an RP-SMA connector, the male connector has the socket, and the female connector has the pin.br br Bulkhead (BH) indicates that the connector is designed to be mounted through a panel or enclosure. It's often used in cases where you want to pass the cable through a wall or metal enclosure.br br Straight (St.) specifies that the connector is a straight design, not a right-angle version.