**Shield:** This value represents the reduction of damage that Sentry receives while the shield is active. At base, the amount of damage you receive while the shield is active will be reduced by 20%.

**Shield Health:** The maximum amount of (pre-reduction) damage you can take before the shield ceases protecting you. A shield health of 600 with a Shield value of 20% protects you from a maximum of 120 damage.

**Damage Conversion:** What percentage of the damage taken (before being reduced) gets converted into damage added to the attack portion of BHS. So with the 65% Damage Conversion, if you take an attack that would have dealt 1,000, your BHS attack power gets increased by 650 (and with 20% Shield, you only take 800 of the 1,000 damage).

(Note however that when I tested it for myself just now, the increased damage from Damage Conversion seemed to be half of what it was advertised as. Not sure if this is a bug or what.)