Precision ground glass stirring shafts, 19mm O.D., hollow, heavy duty. Knob type shafts accept 8091, 8092, 8093, 8100 agitators and can be used in all 19 mm I.D. Trubore® 8059, 8060, 8061 and 8065 bearings. Compatible with 8050 mechanical seal and 13445 PTFE debris-free bearings. Join to stirrer motor using 8124 series chucks. Heavy duty design intended for use with large flasks up to 72 liters.