Applicable skill gems socketed in this item are supported by level 30 Greater Spell Echo Support. All support stats are accounted for, including the mana multiplier.
Greater Spell Echo
Greater Spell Echo causes supported spells to repeat twice (instead of once), but has no cast speed modifier (instead of 51-70% more cast speed). Repeats deal more Spell Damage and have increased Area of Effect per Repeat
Skill Repeats an additional 2 times
Mana Multiplier: 150%
50% increased Area of Effect per Repeat
35% more Spell Damage per Repeat
Can combine with Spell Echo SupportSpell Echo SupportSpell, Support Icon: k Level: (1-20) Cost & Reservation Multiplier: 150%Requires Level 38Supports spell skills, making them repeat when cast. Cannot support Vaal skills, totem skills, channelling skills, triggered skills, instant skills, blink skills, or skills with a reservation.Supported Skills deal 10% less Damage Supported Skills Repeat an additional time Supported Skills have (40-54)% more Cast Speed
Additional Effects From 1-20% Quality: Supported Skills deal (0.5-10)% increased Spell DamageThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Skill Gem you wish to augment. Right click to remove from a socket., that adds 3rd repeat with 105% more Damage. The effective damage multiplier is almost same (around 153%) with or without Greater Spell Echo.