Sapphire 148 hasn't changed since 2008 because any change to the size or position of the Sapphire series Spread-Spectrum conductor arrangment would reduce performance.
Sapphire 148 employs Carbon-Loaded insulation (absorbs RF)On the negative conductors and Nitrogen- Injucted PE (minimal dielectric involvement ) on the positive conductors. In addition , Sapphire 148 includes all 99.99% Copper conductors.