Magnetically operated swinging funnel type, with iron slug totally enclosed.This head maintains reflux ratio constant with changing throughput. The vapor bypass is designed to give accurate thermometer readings. Tapered bulb condenser increases capacity without choking. Side arm joint is 28/11.Thermometer joint is 10/30 with 76 mm immersion. Stopcock bore is 4mm. Supplied with 29/42 column joint. Uses ACE 6588 coil, not included.