Staining jars acc. to Coplin, low shape

made of heavy-walled soda lime glass (pressed glass), for up to 10 microscope slides 76x26 mm, with screw cap made of black urea resin 131.5 with PE foam insert 1 mm, thread size GPI 48-500 (Cat. No. 5458752), in cartons of 10 pcs.
Glass staining articles made of heavy-walled soda lime glass have a relatively high coefficient of expansion. Due to their material they must not be exposed to rapid temperature changes but have to be heated slowly and also cooled down slowly in order to avoid cracks caused by tensions.