Package of 50 Cover Plates, diameter 33mm Back Catalog number: 435028 Manufacturer: HYDRO-BIOS Availability: In the manufacturer's stock Price on request - + Recommended 435012 Counting Chamber for zooplankton,volume approx. 70 Price on request 438040 Plankton Net for quantitative collection with cowl Price on request 438015 Spare Net Part for Plankton Nets No. 438 010 and 4 Price on request