Need a tool to remove screw in covers

[McTrucky]

Hi folks,

Is there a special name for a tool which engages with holes in a screw on cover. It may be that I need to buy a manufacturers special tool, but is there a generic name for these tools? I have used needle nosed pliers, and circlip pliers in the past, but are there any kits available that would be better?

If I am not explaining myself well - one of covers is like a top hat, 15mm across, with four holes roughly 2mm across making a 10mm square. The tool fits the holes like a key.

Another is on a recessed plate inside a threaded tube, with two holes that I need a tool to fit inside the tube to reach the holes to let me unscrew the plate.

Ideally looking for a multi set to fit lots of things like this.

[Doofus]

Multi pin security bit or Snaketongue bit.

[TwinKam]

Pin spanner.

[McTrucky]

Pin spanner! Thanks all - makes googling easier when you what it is called.