What's the point of these adapters? DSE901 to KR808

[Juicehead]

DSE901 to KR808D-1 cartomizer adapter (Silver finish)

It's a DSE901 to KR808 adapter. I though that 901 and 808 were the same threading?

Is DSE901 different from 901?

 

[AngusATAT]

It's for the 901 connections that don't have the air channel that KR808's need.

 

[Juicehead]

Ah that makes sense- thanks!