Here's a link to the main black rifle thread for the Midwest Industries Zenico-style 1913 folder with variable height and length of pull , https://www.canadiangunnutz.com/forum/showthread.php/2345150-MI-Alpha-Stock-1913-folder-adj-height-LOP?p=19412355#post19412355 . For Red Rifles, it should work with a 1913 stock adapter for the Type 81, WK181-C, 7.62x39 MM MCR, and 7.62x39mm SBI LPC manual action (unlike the Renegade, it does not use a return spring, so it can be used with a folder).