The overall length is 6.75".
This will help with the over gassing issue, but may not be the end-all solution for your specific setup.
The Phase 5 Tactical AR-15/M16 Pistol Pigtail Gas Tube was designed to solve timing problems for over-gassed 7.5" AR pistols. The pigtail design causes the tube to simulate a more standard cycle time and helps remedy timing problems without patchwork like a heavier buffer, etc. It fits all barrels using a pistol length gas system with an outer diameter at or below 1”. The diameter of the outside of the pigtail gas tube loops range from 1.46" - 1.56". For best fit, the minimum inner diameter of a quad rail or hand guard should be 1.65"