Package of 250 Base Plates, diameter 27.5mm Back Catalog number: 435035 Manufacturer: HYDRO-BIOS Availability: In the manufacturer's stock Price on request - + Recommended 435011 Counting Chamber for zooplankton, volume approx. 2 Price on request 435010 Counting Chamber for zooplankton, volume approx. 9 Price on request 435100 Folsom's Plankton Sample Divider Price on request