Flat-bottom flasks Duran (refractory)
Set
Refractory flat-bottom flasks made of Duran glass
Flat-bottomed flasks for use as reaction vessels or reservoirs in distillations or extractions.
With reinforced rim, narrow neck. Durang glass has a slightly thicker wall and is resistant to extreme thermal shock (which does not actually apply in high schools).
Multiple variants available: see below for an overview