The Lone Wolf Arms Flash Hider does not require a crush washer if attaching to a pistol. A washer is recommended if attaching to a rifle.
The Lone Wolf Arms Flash Hider is offered in multiple different thread pitches depending on the caliber it is designed for. MPN:LWD-FH45 is threaded .578x28 and is designed for .45 ACP or smaller. MPN:LWD-FH9 and MPN:LWD-FH409 are threaded 1/2x28 and are designed for .45 ACP and.40 S&W. MPN:LWD-FH10 and MPN:LWD-FH40 are threaded 6/16x24 and are compatible with 10mm as well as .40 S&W.
Lone Wolf Arms does not provide the length of these Flash Hiders. I would recommend reaching out to them directly for more information regarding dimensions.
MPN:LWD-FH40 would be the compatible model.
Not if attaching to a pistol.
Yes, as long as you select the correct caliber and threads to match your Sub2000.
Yes, MPN: LWD-FH45 will be compatible.
LWD-FH45 is the model that will be compatible with the Glock 21 .45 ACP.
They are not the same threading, however the Sig OEM threaded barrel for P220 is .578x28 threaded so it should work. I've provided a link to the barrel in question below as a reference:
https://www.opticsplanet.com/sig-sauer-45acp-barrel-for-p220-tb.html