LOCK&LOCK
 
   
 
 
 
silicone types
   
  There are regular silicone and Lock&Lock silicone. Here is the difference.
   
 
Generic silicone
A generic silicone with the full center does not give a close seal and tends to stiffen to cause inferior tightness and lockage
 
Lock&Lock silicone
silicone hollow inside has superior compression and restoration power for airtight lockage.