Part comparison - Amphenol RF vs RFX

What does is the difference between Amphenol’s RF and RFX (called out by RFX suffix) connectors? Example 31-320 vs. 31-320-RFX

RFX connectors. RFX is specifically designed for applications that do not require performance above 1 ~ 3GHz. RFX connectors are not for use in military system applications. RFX connectors are generally less expensive than MIL-Spec and industry standard connectors.