Tube two-sided openly! The tubes can be closed for breeding purposes simply on a side with cork or filter sponge. To the removal of the boy fishes simply remove the sponge and take the boy fishes. Size of 2 middle interior diameters small ca. 2,7cm ca. Select 10 cm long (for small L-Welse z.B.L46, L174 and small Pekoltia-types) for animals from 8 cm lengths size 3! In the colors brown.