Due to extremely high demand extension tube orders will take 4-6 weeks to complete and ship. This is a kit that allows you to attach a Picatinny rail to your M4. It fits over the magazine tube close to your fore end and is clamped down by new supplied extension to which the barrel is then held with your existing end cap. The components are made out of 6061 Aluminum with hard black anodizing. It is compact yet functional and allows you to retain your existing fore end. This item is not a magazine extension.
Please download fitting instructions by clicking here
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