Keidy supply sintered bronze muffler/Silencer with following type: 

• 1/8''     NPT   
• 1/4''     NPT  
• 1/2''     NPT  
• 3/4''     NPT  
• 1''        NPT
• 1 1/4''  NPT
• 1 1/2''  NPT
• 1 3/4''  NPT
• 2''         NPT