Parts of a Trombone

1. tuning slide
   
   
2. mouthpiece
   
   
3. bell
   
   
4. water key
   
   
5. main slide
   
   
6. second slide brace
   
   
7. first slide brace
   
   
8. slide lock ring
   

Reference: http://commons.wikimedia.org/wiki/Image:Trombone.svg