Set of 12 filter sheets, each measuring 8.9 x 8.9 cm. You can cut these sheets to fit the filter drawer of your enlarger.
The gradations are categorized as follows: 00 – 0 – 0.5 – 1 – 1.5 – 2 – 2.5 – 3 – 3.5 – 4 – 4.5 – 5.
From 00 to 3.5, use the same exposure time; from 4 to 5, double it.