Home About Us Resources Products Services Contact Us You have choosen multiwall carbon nanotubes, hollow structure. Purity > 95%,residuals may include iron, sulfur. OD 15 ± 5 nm Length 5-20 microns SSA 200 - 400 m2/g [back] PD15L520-50g$4,500.00 updated: 03/29/2017