All ddr ram is capable of dual channel mode; the designation is determined by the motherboard chipset and the ram slots you select. Always install identical sticks in pairs in the correct slots and you'll be running in dual channel. Google your motherboard manual if needed and read it.
ddr2 is the ram spec. Dual channel has nothing to do with the type of ram, just the speed. Be sure of what you need before you order; cpuz will let you know the ram brand and speed your board is using. If you need more ram, list your board make and model number, or system model number for dell, hp, etc. Then you'll get better advice.