You can find the Agency Arms 417 Single Port Compensator for Glock Gen3 Black here.

The Agency Arms 417 Compensator for Glock features a single chamber design with a single vertical port to help keep you on target and allow for faster follow-up shots. The 417 Compensator also features a front sight hole that allows you to transfer your existing front sight from your slide to the comp. Includes 2 Set Screws with an Allen Wrench and Thread Locker.

Firearm: Glock 17, 19 and 34 Gen3. NOT COMPATIBLE WITH CONVERSION BARRELS. AlphaWolf, SilencerCo, Fortis MFG, Faxon Firearms, and OEM threaded barrels are not compatible with this compensator.
Threads: 1/2x28
Color: Black