You have a better than normal chance to resist turning.
Prerequisite: Undead type.
Benefits: You are less easily affected by clerics or paladins than you normally would be (see Turn or Rebuke Undead). When resolving a turn, rebuke, command, or bolster attempt, add +4 to your character level (monster Hit Dice plus class levels) to determine your Hit Dice for turn, rebuke, command, and bolster attempts. For example, a 4 HD wight with this feat is treated as an 8 HD undead for the purpose of turn, rebuke, command, and bolster attempts, even though it is a 4 HD creature for any other purpose. A vampire that already has +4 turn resistance adds an additional +4 with this feat, for a total of +8.
Source: Libris Mortis, page 27.