Unfortunately, Bozzle has been discontinued.

However there are some great new alternatives to this nozzle:

• Silicon carbide Nozzle By Phaetus
  
• Bondtech CHT BiMetal RepRap V6/M6 Coated Nozzle
  

What is it?

Fully Tungsten Carbide nozzle (no insert) - The Last Nozzle You Will Ever Need

Specs:

• 0.5mm Tungsten Carbide nozzle CHT-like flow
• High Flow, low clog geometry 
• High hardness for sustained printing with Filled / Abrasive Filaments
• Reduced pushing force to get more from your extruder
• Increased layer bonding strength when printing at same temperature as steel nozzles
• Reduced filament sticking with some filaments
• 6mm flats to fit inside nozzle shields
• V6 and Mk8 compatible