All the flasks from Laboyglass are with interchangable grounded joint,the joint was well grounded both by machine and hand to ensure good sealing performance, the joint size can be made according to US standard to BS standard,the most common sizes are *4/*0,*9/*2,*4/*0,*9/*2,*4/*5,*5/*0,*5/*0.
The glassware are ideal for the seller on amazon,and also suitble for the end user ,the factory.
We can supply the custom glassware and semi-products for example the joints.