Systema lists the type-1 SPECIFICALLY as an AK-47 length cylinder.
http://www.wgcshop.com/pcart/shopper...m=SYS-ZS-04-17
Most people actually aren't aware of its existance, because most manufacturers don't create that intermediary cylinder between the Type-0 (full length) and Type-2 (1/4 ported), which are the two most commonly used sizes.