I have the 6.8 version on my 6.8 SPC.https://www.opticsplanet.com/vg6-precision-gamma-65-bbss-muzzle-device.html
VG6 Precision Gamma 65 Muzzle Device APVG100016A Color: Black, Finish: Black Nitride, w/ Free S&H
These are excellent. I have 5, including one on my Bergara 6.5 CM.