what is the Single-walled carbon nanotubes?

Name: Single-walled carbon nanotubes
Description:
Many different types of single-walled carbon nanotubes, single wall can reach the highest purity greater than 90%
1, purity (Purity): SWCNTs> 90% (SWNT> 60%)
2, diameter (Outer Diameter): <2 nm
3, length (Length) :5-15μm
4, the specific surface area (Special surface area) :500-700 m2 / g
5, thermal conductivity (Thermal conductivity): ~ 4000W / m · k
from:Rare Metals