Jacketed reaction flask with round bottom. Flat flange is grooved for using an o-ring (instead of a flat gasket) to seal to a head. Jacketed for temperature control of ingredients. Supplied with CAPFE o-ring. Codes -01 thru -04 have 28/15 o-ring ball joints on inlet/outlet. Codes -301 thru -304 have #11 Ace-Thred inlets/outlets for use with 3/8in ID tubing. For reaction heads see 6512, 6513, 6515 heads. See 6510 for clamps.