This Designer Kit is for 3-port SMA used for designing a Frequency Mixer, Power Combiner/Splitter, Directional Coupler,c etc. Fit size of the PCB 1"x1"x0.031".  I have few PCB designed to use this encloure, link below.

Kit include:

• Machined Housing and Cover, 1 ea
• SMA 2-Hole Flange Jack Receptacle Connector, 3 ea
• 2-56X3/16 Hex Socket Cup Head Screw (for SMA Connector), 6 ea
• 2-56X3/16 Pan Head Screw (for mount PCB), 6 ea
• 2-56X1/4 Flat Head Screw (for Cover), 4 ea

Some PSB will fit into this encloure:

https://www.ebay.com/itm/Develop-PCB-Mini-Circuits-ADE-JMS-Mixer-Qty-4-/150202588411?hash=item22f8c59cfb

https://www.ebay.com/itm/Develop-PCB-Mini-Circuits-ADP-JPS-Power-Div-Qty-4-/150201933961?hash=item22f8bba089

https://www.ebay.com/itm/Mini-Circuits-5-1000MHz-20dB-Directional-Coupler-ADC-20-4-designed-PCB-/400164854364?hash=item5d2baf1a5c