WaterMark 777920 [77920] Student Plankton Net, 333 µ (Mu), 15cm x 50cm This 15 cm diameter x 50 cm length Nitex® plankton net comes with a stainless steel ring and bridle, clear polycarbonate cod-end assembly with valve action drain, and 10.0m line. Nitex® nylon nets are available in 80 µ, 153 µ, and 333 µ mesh sizes.