I have a choke that is similar to that one. My choke is 20 years old and has the MD 100 number on it. It throws an awesome pattern with the Hevi #6 shot. I spent several days searching for one for the Father in-law ( he was not getting mine). Found one for 15.00, He shoots the 3.5 #6 out of his 870. That thing puts up 210ish in the 10 at 40.