SIR..i do not know, exactly the name for this material,in international market, but i can simply explain , we can attain this material from packages of refrigerators, tv s, A/C s and many house hold appliences...i hope it may also known as EXPANDED POLYSTRENE...i was making scaled models from the age of 6,and i born here in INDIA, in kerala state,a state, not much advanced in science..here no balsa is available...so i turned to this material, along with drawing papers,for making super structures and details...i started to make fighter planes at first...then after making 200 + aircrafts, now turned in to war ships...its powered by a 6 volt, 5 amps SLA battery, found in emergency lamps...the motor is taken from an R/C helicopter,performs well...i do not have any professional radio system with me, so it also made myself...its working with a freequency of 40 Mhz, and the outer cover of the controller was taken from a chinese toy...i will post all regarding photos of my next model,from begining, its a fast patrol boat, for my NAVY...its almost compleated...