The Kirby Morgan SL17B includes the Quad-Valve Exhaust System and Yoke Neck Clamp assembly w/ Latch Catch. The Helmet Retainer (chin strap) and Yoke Retainer (yoke strap) make it virtually impossible to have the helmet come loose.
Other features include:
• Superflow Regulator
• Brass Handle
• Chin & Yoke Strap Kit
• Bottom shell entry is slightly larger than other models