Reference article
Turtle shell
Turtle shell is a costume with 45% base battle protection.
Protection and elements
This item supplies 45% base protection. Its resistance is water and its weakness is electricity. In battle, resistance doubles the item’s protection contribution and weakness halves it. Endurance and the other equipped armour piece also affect the final damage.
Buying
Buy it when stocked in the relevant shop. The inspected desktop/console price is 1320 bronze-equivalent 
Coins; iOS, Android and CrazyGames use 2640. Stock depends on shop type and the duck’s progress.
Equipment mastery
Owned equipment accumulates mastery during battles. Mastery changes equipment performance; see 
Equipment for the shared system.