Place of Origin: China MATERIAL :borosilicate 3.3 Size: 250ml,50ml,100ml,500ml, Joint:14#,24#,19# features:(1)item:Flask reaction beside glass stopcock(2)material :heat resistant 3.3 borosilicate glass(3)sizes:50/14 100/14 100/24 250/24 500/24(4)we can provide many laboratory glasswares.more information please contract us. Flask reaction beside glass stopcock