2240
You will need this adapter.
https://donnyfl.com/products/crosman-2240-adapter-a30?_pos=1&_sid=dcd8ab433&_ss=r

I recommend the Tatsu .22/25 1/2x20 #S31 for the 2240. The larger size will reduce the chances of pellet clipping.
https://donnyfl.com/collections/ldc/products/1-6-x-4-25-inches-tatsu?variant=33070871183403


I recommend the Tanto .22/.25 1/2x20 #S69 for a slim look on the suppressor. 

https://donnyfl.com/collections/ldc/products/1-22-x-5-inches-tanto?variant=33070828126251


2240XL


The 2240XL comes with a 1/2x20 threaded barrel.


I recommend the #S31 Tatsu .22/25 1/2x20 for the 2240XL. The larger caliber size will help reduce the chances of pellet clipping.

https://donnyfl.com/collections/ldc/products/1-6-x-4-25-inches-tatsu?variant=33070871183403


I recommend the Tanto .22/.25 1/2x20 #S69 for a slim look on the suppressor. 

https://donnyfl.com/collections/ldc/products/1-22-x-5-inches-tanto?variant=33070828126251