Dropping funnels, cylindrical, with pressure equalising tube

Borosilicate glass 3.3. Cylindrical shape, with pressure equalising tube. With NS socket and interchangeable PE stopper, plug with retaining device. With graduations for reading of the approx. volume.
Two types available:
- With solid glass key
- With PTFE key
Capacity 500 ml
NS 29/32
Bore 4.0 mm
Grad. 10 ml
Keys solid