The difference between 10 L portable liquid nitrogen tank with or without lock cover

What's the difference between a 10 liter portable liquid nitrogen tank with lock cover and without lock cover?

1. The liquid nitrogen tank has a lock cover. In structure, a lock cover is added around the neck. It can be used for frozen semen storage and laboratory sample storage!

2. Liquid nitrogen tank without lock cover, usually used for easy dumping or transfer occasions, such as stage wedding smoke production! Ice cream making, etc.