PoE2
Slower Projectiles
Support
Projectile
Requires: Level 1
Support Reqirements: +5 Dex
Supports projectile skills, making those projectiles travel more slowly.
Supported Skills have 20% less Projectile Speed
Place into a Skill's Support Gem socket in the Skills menu to apply its effects to that Skill. You cannot have multiple copies of the same Support Gem socketed at the same time.
PoE1
Slower Projectiles Support
Support
Projectile
Level: (1–20)
Cost & Reservation Multiplier: 120%
Requires: Level (31–70), (52–111) Dex
Supports projectile skills.
Supported Skills have (20–30)% less Projectile Speed
Supported Skills deal (10–19)% more Projectile Damage

Additional Effects From Quality:
Supported Skills deal (0–10)% increased Projectile Damage
This 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.