Why Choose Jointed Flat Bottom Boiling Flasks for Your Lab Needs? Double-neck Flat Bottom Flasks are essential pieces of lab equipment, allowing for simultaneous operations via their double-neck design. Their ability to facilitate control over complex experiments and reactions makes them invaluable in chemical research. Furthermore, reflux condensers can be set up with these flasks, allowing for additional versatility. Flat Bottom Jointed Two Necks are manufactured from Borosilicate Glass which offers excellent resistance to chemical corrosion and thermal shock. Brand: Science Equip Note: End User Declaration is required for the purchase of this product. Packing: 1Pc/Pk Item Code Nominal Capacity (ml) Centre Socket Side Socket Approx. overall height (mm) 15.00.101002 100 24/29 19/26 100 15.00.101002A 100 24/29 24/29 100 15.00.101012 250 24/29 19/26 140 15.00.101012A 250 24/29 24/29 140 15.00.101042 500 24/29 19/26 163 15.00.101043 500 24/29 24/29 163 15.00.101122 1000 24/29 24/29 200 15.00.101172 2000 34/35 24/29 240 15.00.101182 3000 34/35 24/29 240 15.00.101192 5000 34/35 24/29 260 15.00.101192.24 5000 24/29 24/29 260 15.00.101193 10000 34/35 34/35 15.00.101194 20000 34/35 34/35