It´s balsa. Nothing but the best contest grade we could find. I must give credit here to the builder - Ulysis Ibarra of Mexico City for a fine job. He´s the best scratch builder there is, in this part of the world.
At this altitude (8,000ft+ ASL), we go for the lowest weight possible. The "Tempoon" really snaps and penetrates well, but I have´nt flown in strong winds yet. I have a Dennis Hunt built wood Viper 2M (about 9.7lbs) which is great in the wind.
BTW Mike, have you heard any rumours about a change in the weight limit??