Unknown Strength Boots

Item ID 470071 Name Unknown Strength Boots
Old shoes that have been eroded by an unknown force.
Whenever the wearer exerts force, he can feel the boots react.
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For each 2 Refine Levels:
ATK +15
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For each 3 Refine Levels:
MaxHP +120
MaxSP +8
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Refine Level +9:
Increases Attack Speed (decreases After Attack Delay by 7%).
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Refine Level +11:
Physical attacks have a random chance to increase STR by 175 for 10 seconds.
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Refine Level +13:
Increases Melee Physical Damage by 7%.
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[Bonus by Grade]
[Grade D]: Physical attacks have a random chance to increase STR by 25 for 10 seconds.
[Grade C]: Physical attacks have a random chance to increase STR by 25 for 10 seconds.
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Type: Shoes
Defense: 60
Weight: 70
Armor Level: 2
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Requirement:
Base Level 230
Weapon Level 0 Identifier MD_Airboat_Boots
Attack 0 Type Armor
MATK 0 Equip Locations Footgear
Defense 60 Equippable Jobs None
Range 0 Equip Gender Both (Male and Female)
Slots 1 Equip Upper None
Weight 70 Min Equip Level 230
NPC Buy 0 Max Equip Level None
NPC Sell 0 Refineable Yes
Credit Price None Trade restriction None
Item Script 
.@r = getrefine();
bonus bBaseAtk,15*(.@r/2);
bonus bMaxHP,120*(.@r/3);
bonus bMaxSP,8*(.@r/3);
if (.@r>=9) {
   bonus bAspdRate,7;
   if (.@r>=11) {
      autobonus "{ .@g = getenchantgrade(); if (.@g >= ENCHANTGRADE_D) { .@val = 25; if (.@g >= ENCHANTGRADE_C) { .@val += 25; } } bonus bStr,175+.@val; }",1,10000,BF_WEAPON;
      if (.@r>=13) {
         bonus bShortAtkRate,7;
      }
   }
}

Set Script
Song of Hero
Unknown Strength Boots 
bonus bAllStats,10;
bonus bDelayrate,-25;