Lenco speed control screws

I have to adjust the speed controls on my Lenco table. Can anyone tell me what type of screwdriver I need to loosen the screws?

I thought they were philips head screws, but after trying a few different phillips screwdrivers it appears I need a certain size torx driver. I don't have any of these and any insight on the size of the torx driver needed or if I am off base and need something else would be much appreciated.

A Phillips screwdriver of the right size in enough. I do it so with all my Lenco's and there is no special screwdriver mentionned in the manuals.
If difficult to unscrew, tap gently with a small hammer on screwdriver in the screw.