The ZWO LRGB 31mm filters are not mounted in a cell and are designed to fit in the ZWO EFW filter wheels.
The width of its bandpass is balanced with the spectral response of the ZWO cameras with the ratio 1:1:1. This means the exposure of each channel will be equivalent.
The L filter is a standard UV-IR cut filter, but each filter cuts off the ultraviolet and infrared so there is no need to use the L filter in combination with the colour filters.
The surfaces of the filters are optically polished and fully multi-coated.
