Lone Wolf is selling a compensator designed to work with their barrels (and I presume an others that meet the specifications) in 9mm, 40S&W, and their 9mm conversion for 40 S&W.
The Alpha Wolf compensator offers a unique advantage to the discriminating competitive shooter. The redirection of gas vertically provides a genuine reduction in muzzle rise. The result allows the shooters sights to remain on target or realigned quickly providing faster accurate follow up shots.
They do mention that light (or reduced power loads) will not work reliably with the comp. They also recommend the use of their LWD stainless guide rod and ISMI reduced power recoil springs.
If you are interested, you can buy one at: https://www.lonewolfdist.com/Detail.aspx?PROD=919522&CAT=313
Thanks to Hrachya for the find.