The Sons of Liberty Gun Works AR-15 6mm MAX Precision SPR Threaded Barrel does not include a gas tube or gas block.
The Sons Of Liberty Gun Works Precision SPR 6mm MAX 16" Threaded Barrel utilizes an intermediate 13.65" length gas system. The 14.5" barrel uses a mid length gas system.
No. 6mm Max is a necked down version of the straight walled 350 Legend case. The case diameter is 0.390" which is slightly larger than a 5.56 NATO however it has a rebated rim which makes it compatible with the 0.378" bolt carrier group used in 5.56 AR-15 rifles.