How to query to select a struct of array of struct column within a table?

How would I query to select length(int) which is within the array ‘details’ which is within the ‘packets’ column. Hopefully the image attached will explain better than me!

I’ve tried SELECT packets.details.length FROM test.ssh_data which doesn’t work.

This gives me the following error: illegal column/field reference 'packets.details.length' with intermediate collection 'details' of type 'ARRAY<STRUCT<datestamp:STRING,length:INT>>'