I meant to put this in the last post, from my phone, but that didn't work.
You can find the differences here. http://www.brianenos.com/forums/index.php?showtopic=219243
yes
http://www.midwayusa.com/product/316916/briley-spectrum-mach-1-extended-choke-tube-benelli-except-crio-beretta-mobilchoke-12-gauge?cm_mmc=se_service-_-shippingconf-_-shippingconf-_-ProductShippedTodayLink
Or
http://www.powerfactorshooting.com/ProductDetails.asp?ProductCode=BENELLI-MOBILE-CHOKES