An immobile, crystalline, web-like globe surrounds you. When the ablative sphere winks into existence, it provides you with improved cover (see below). The barrier does not impede a spell's line of sight or effect.
The sphere is 1 inch thick per caster level, has hardness 5, and 3 hit points per inch of thickness. When an ablative sphere loses hit points, the level of cover it provides is reduced. When the ablative sphere has lost one-third of its hit points, it provides cover instead of improved cover. Once it has lost two-thirds of its hit points, it provides only partial cover. Finally, when the ablative sphere's hit points reach 0, the globe is destroyed. When an attack reduces an ablative sphere's hit points to 0, you take any remaining damage.
In some cases, such as attacking a target hiding behind an arrowslit, cover may provide a greater bonus to AC and Reflex saves. In such situations, the normal cover bonuses to AC and Reflex saves can be doubled (to +8 and +4, respectively). A creature with this improved cover effectively gains improved evasion against any attack to which the Reflex save bonus applies. Furthermore, improved cover provides a +10 bonus on Stealth checks.