Ava's accumulator is an item that is worn in the cape slot that resembles a backpack. It has a hidden effect that is very useful among rangers and is most likely why this is the most used ranged item in the cape slot.
Anyone can buy Ava's accumulator from the Lowe's archery store located in Varrock market or Varrock square. The accumulator only costs 1,000 coins.
Commonly regarded as the most useful range effect, the Ava's accumulator's effect saves the user both time and money. Each use of ammunition has a chance of not being used, except for when using Chinchompas. This effect will always work when the accumulator is worn. This effect is also emulated by the Completionist cape.