Crosman Moderator advice

I just received my Crosman 2240 xl. Have watched several videos that show that this gun makes quite a crack when fired. I don’t want to attract attention in the neighborhood so I’m looking for a moderator to attach to the end of the barrel. I’m thinking something in the neighborhood of 6 inches preferably with a squared end rather than tapered. Any and all suggestions would be appreciated thank you in advance…. Alan
 
You can use any moderator you like with one of these:
The XL has a threaded barrel.