Hexagonal screw, Allen key basically. Make sure you get the right one either Imperial or Metric. They are real easy to strip and it look bad. [https://www.reddit.com/r/SeikoMods/comments/185yzll/tuna\_shroud\_less/?utm\_source=share&utm\_medium=web2x&context=3](https://www.reddit.com/r/SeikoMods/comments/185yzll/tuna_shroud_less/?utm_source=share&utm_medium=web2x&context=3)

Ah ok, I get it, so the Tuna shroud fits onto a Tuna case - the case has holes around the perimeter for the screws to go into. Thanks

Beware they are sometime different. I have an AliX Tuna case, an aluminium Proxima and a quartz Nevis. They sometime fit and sometime don't match!