The Piranha was designed to run quietly with a titanium hull and AIP technology. It can carry two torpedoes or mines in those bulges running down the sides of the "sail". Also capable of delivering commando types. Only two built, both mothballed. Kit produced by AIM out of Ukraine. I had never heard of them before I ran across it on eBay. Currently in work on the HobbyBoss 1/200 scale Yuan-class fast attack...yet another ChiCom entry. Nice kit...about 2 inches longer than the Song-class I just sent you pix of. I nudged Phil to get in touch and bring you up to date. I bleeve I have that Academy kit and IIRC, it is one of those motorized "tub toy" things. We need Revell or even Trumpeter to do a credible Type IX in 1/144!