QANVEE Sponge Filter / Sponge Replacements (YX-300 / YX-600)

• Ultra-thin design, saving in-cylinder space.
• Both mechanical and biological filtering functions
• Comes with tiny spherical filtration balls for cultivating beneficial bacteria.
• Perfect replacement for air stones, in small and simple setups. 
• Works great for fry tanks

Comes in 2 sizes. 

YX-300 / YX-600