Highest gas dispersing capability available. Can disperse nearly six times the gas handling capability of the D-6 or Rushton impeller. Unloads less than the CD-6. In fact, the unloading is nearly all due to the change in effective density of the gassed liquid. The mass transfer capability is on the order of 10% better than the CD-6. Unlike many other gas dispersing impellers, the BT-6 is relatively insensitive to viscosity.