The Eclipse PWR Stock is designed for quick adjustment – maximum stability and improved sighting – making it a supremely effective upgrade to your tactical loadout. Designed to accept HPA tanks with a max external diameter of 51mm/2 Inch – the Eclipse PWR Stock is an enhanced buttstock that combines to give both tank protection and a fully integrated profile. The lever operated adjustment arm allows you to quickly position the PWR Stock to any of the 11 numbered lock-in points. The ergonomically contoured shoulder grip reduces slippage to help improve accuracy. Features Tough light GRN construction Lever operated adjustment arm extends quickly to 11 lock-in points Positive shoulder grip reduces slippage Accepts HPA tanks up to a max diameter of 51mm/2″ Compatibility Designed for use with these models of markers/setups: Eclipse Emek MG100 Emeks with EMC Kit installed. Etha 2 with EMC Kit installed. Composition Glass Reinforced Nylon (GRN)