The GSL Smooth thread protector is perfect for the MP5 platform to allow the GSL Phoenix or the GSL Scorpion suppressors or Fatman or any trilug suppressor to securely fasten to the trilug mount while protecting the threads of the weapon.
1/2×28 Smooth Thread Protector (0.625″ long)
Check your thread protector with a ruler to ensure you have the correct length. this listing is for the 0.625″ smooth thread protector in 1/2×28. Check out the 0.5″ thread protector here