This listing is for 3-30g tubes of GD900. Great for system builders, miners, led installers, etc. I know I will seem a bit biased as the seller but it's pretty good @ 4.8 w/mk for less than a dollar per gram shipped. I only sell items I use and trust. I digress. A lot of sellers won't even tell you the thermal conductivity upfront. This is less dense than arctic silver. It's more similar to NT-H1, or MX-4, not electrically conductive but decently thermally conductive, just more affordable per gram to get similar results. 

From the supplier:

Color: Gray

Specific Gravity: 2.3 G/Cc

Electrical Conductivity: NA

Thermal Conductivity: 4.8 W/M-K