Strike Industries JCOMP Gen2, Compensator, 308 Win/7.62MM, Black, 5/8X24 SI-JCOMP2-308/7.62 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 .308/7.62x51mm. Now also compatible with Oppressor and FerFrans concussion reduction devices.