Gell 1.3mm Unequally Spring for JM Gen.8 M4A1/ JM Gen.9 M4A1/ JM Gen.10 - ACR - Silver

Gell 1.3mm Unequally Spring for JM Gen.8 M4A1/ JM Gen.9 M4A1/ JM Gen.10 - ACR - Silver. Special steel with anti-fatigue oxide layer, low attenuation .Adapted to JM Gen.8 M4A1/ JM Gen.9 M4A1/ JM Gen.10 - ACR gearbox modification upgrade .Unequal is more resistant to fatigue and more durable. After the conversion is successful, the initial speed can be greatly improved. .Note: 1. Applicable age: 14+; 2. Modification requires a certain amount of hands-on ability, please be careful to buy; 3. The specification of the spring is due to manual measurement, it is inevitable that there is a certain error, please do not buy if you are concerned; This product only guarantees the quality of the spring, and does not guarantee the range of the initial speed. Because the initial velocity is affected by many factors, if any link is not completed, it will affect the initial velocity. Specifications: .Color: Silver .Material: Special Steel .Product Dimensions: 14.5 x 1.4 x 1.4cm .Product Weight: 10.4g