Spellbound Cerulean Drum

Instrument

Item Details

Utility 20.67
Bonus Level 11
Dyeable No
Sellable Yes
Tradeable Yes

Restrictions

Level Required Any
Usable By
All Classes

Magical Bonuses

Basic
Dexterity 7
Heat Resist 4%
Spirit Resist 4%

Raw Item JSON

{
  "sell_value" : 4176,
  "bonus_level" : 11,
  "sources" : {
    "stores" : [ "Hib Aurulite 20b" ]
  },
  "flags" : {
    "dyable" : false,
    "emblemizable" : false
  },
  "icon" : 2971,
  "utility" : 20.666666666666664,
  "delve_text" : "Realm: Hibernia\n \nMagical Bonuses:\n- Dexterity: 7 pts\n- Spirit: 4%\n- Heat: 4%\n \n \n \nBonus Level: 11\n",
  "salvage_amount" : 5,
  "artifact" : false,
  "material" : 35,
  "name" : "Spellbound Cerulean Drum",
  "usable_by" : [ 0 ],
  "realm" : 3,
  "id" : 46229,
  "category" : 4,
  "bonuses" : [ {
    "id" : 1,
    "type" : 1,
    "value" : 7
  }, {
    "id" : 17,
    "type" : 5,
    "value" : 4
  }, {
    "id" : 10,
    "type" : 5,
    "value" : 4
  } ],
  "ability_tags" : [ ]
}
How is utility calculated?