Failing a Skill Check while repairing:

Prevents the Generator Explosion.
Applies the default Regression penalty.
Applies an additional Regression penalty of 5/4/3 percent.
Technician reduces the audible range of your Generator-repairing noises by 8 metres.

After hitting a Great Skill Check while repairing or healing, Hyperfocus gains 1 Token, up to a maximum of 6 Tokens
For each Token, the following stack-able effects are applied:

Increases the Skill Check Trigger odds by +4 percent per Token.
Increases the Skill Check Rotation speed by +4 percent per Token.
Increases the Skill Check Bonus progression by 10/20/30 percent of its base value per Token.
Hyperfocus loses all Tokens when succeeding a Good Skill Check, failing a Skill Check, or if the action is interrupted by any means.

Upon completing a Healing action on another Survivor, they benefit from the following effect until the next time they take damage:

Increases their Action speeds in Healing, Unlocking, Cleansing, and Blessing by 12/14/16 percent.

After cleansing a Totem, Overzealous activates:

Increases your Repair speed by 6/7/8 percent if it was a Dull Totem.
Increases your Repair speed by 12/14/16 percent if it was a Hex Totem.
Overzealous deactivates when losing a Health State by any means.

Increases the Efficiency of your Items by 15/20/25 percent.
Streetwise extends its effect to all other Survivors within 8 metres of your location and lingers for 15 seconds.

When you unhook a Survivor, the rescued Survivor benefits from the following effects for 4/6/8 seconds:

Scratch Marks and Pools of Blood are suppressed.
Additional 7 percent Haste Status Effect, boosting their Movement speed.
Guardian reveals the Killers Aura to you for 8 seconds.