– Tamper Resistant Lockwing Cap – Full Port Design to Accommodate Industry Leading Stop Changers – Lockwing Accommodates Standard Barrel Locks – Maintenance Free Design – Patented Security Shutter and Lockwing Tab: US Patent No. 6,648,009 – 2 FKM O-Rings – 100% Leak Tested – 100% Made in Italy – Leakproof Stem - Lifetime Warranty