Yep it comes with a case (I was surprised, didn't read the small print!) but I wanted a more secure one with cable retainers so here it is.

If you are using these for a high voltage application please ensure that you have the correct knowledge to build what you are attempting, else seek help or maybe try another project as electricity can kill, start fires and be generally unpleasant. 

There are the following case options:

• Basic case (no mount options)
• 12mm pipe mount option (yes its weird, I am using it for something!)
• Magnetic mount option with 8x2mm disc magnets
• Screw mount option

Required For Assembly

• 8x M3 Ruthex or similar sized inserts
• 8x M2 CNC Kitchen/Ruthex or similar sized inserts (+4 for 12mm pipe mount option)
• 8x M2x6 screws and washers
• 8x M3x8 screws and washers
• (For 12mm pipe option) 4x M2x14 or M2x16 screws and washers
• (For magnetic mount option) 6x 8x2mm disc magnets

Assembly

Most of these inserts need a bit of care so as not to melt the case. I managed to do it cleanly with a little care.   Install a total of 8 M3 inserts in the lower and upper corners of the main body.   Following this, install 8 M2 inserts along where the cable retainers are placed.
If you are using the 12mm pipe mount option, install 2x M2 inserts in the holes in each side.
If you are using the magnetic mount option, put a dab of glue over each hole and poke the magnets in with a handy tool. Wipe any excess glue away and leave to dry.   The magnet placement was chosen to be this was as this board has mechanical relays which may be influenced by the magnets being closer or under the relays.
Install the cable retainers with the M2x6 screws and M2 washers.   Install the PCB in the base with an M3x8 screw and washer in each corner.
Attach the case lid with 4x M3x8 screws and washers.
If using the 12mm pipe option attach the clips with the M2x14/16 screws and washers.   Congratulations, you are done!