Strike Industries JCOMP Gen2, Compensator, 14-1 LH, 7.62X39, Black SI-JCOMP2-AK The SI JCOMP Gen2 is the classic Type 89 compensator re-engineered and updated for the 21st century. Due to end user feedback" the favorite features of the original are retained" but the J Comp now features increased muzzle rise compensation" and is available in 7.62x39mm and .308/7.62x51mm in addition to 5.56x45/.223. Now also compatible with Oppressor and FerFrans concussion reduction devices.