Both units have their place - hence why there are 2 offered. The wrist unit covers a larger area and has greater power for the total device. It is very good to put light into the blood as it flows through the wrist area and gets distributed to the rest of the body. Some people have also reported using it on sore muscles, or other conditions where surface or close to surface issues exist. The twin laser unit is good for nasal or ear applications.
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