socketed gems supported by

so i'm looking at helms on trade

+3 to Level of Socketed Minion Gems
Socketed Gems are Supported by Level 18 Minion Life
+21 to Intelligence
15% increased Rarity of Items found
Minions have 20% increased maximum Life
Nearby Enemies take 9% increased Physical Damage
+17 to Strength and Dexterity

the helm stats are listed like this.
does the "supported by level 18 minion life" stack with the "minions have 20% increased maximum life"? or is the 20% the result of the level 18 listed further up?

Thanks for help, tried searching forums for about 20 minutes and couldn't find anything related

Yes it does. That 20% increased life modifier basically makes up for the fact that the gems in the helmet cant get any quality.

And they are both part of the same mod.

The "Socketed Gems are Supported by ..." mods always come with a relevant secondary mod, and you get the benefit of both. Aside from some support mods on weapons, that secondary mod is also global rather than local to the skill you put in the item.

So if you stick only Raise Zombie in that helm, only they will get that minion life gem support. But all your minions will get the benefit of the secondary increased life mod.

thank you for explaining!