Prometheus 6.03mm EG Inner Barrel for AEG - 229mm Sniper Pistons Note there are different variants

Note there are different variants of this gearbox for MP5s

Objective diameter 50 mm

It is mounted on lower rail handguard by 4 screws and receiver by 1 screw

This is not for regular AEGs (G2 models only)

And at long last

Prometheus 6.03mm EG Inner Barrel for AEG - 229mm Sniper Pistons Note there are different variantsInner bore width of 6. 03mm with a 0. 01mm tolerance. MP5A4, A5, SD5, SD6, Spetsnaz. Solid BB stability and accuracy, made with enhanced stainless steel (SUS). Inner barrel bore width of 6. 03mm with a tolerance of 0. 01mm, made of stainless steel for superior strength necessary to maintain accuracy without the need for special coatings. The barrel is arguably the heart of any airsoft gun and determines various performance factors such as velocity