Across International Heavy Wall Short Path Distillation Head With Straight Drain, 5LThe Ai heavy wall 5L packable short path distillation head with vacuum jacket offers you a lot of new changes over its previous version. Larger vacuum jacket means less heat loss during distillation Increased internal diameter throughout the whole head for more efficient fractioning and condensation of vapor with zero clogging. 75% more efficient than its predecessor. Fine grinded joints gives you higher ultimate vacuum level Heavy wall for durability