Using a large-object output parameter – PB Docs 2017

You can define a large object (LOB) as an output parameter for an
Oracle stored procedure or function to retrieve large-object data. There
is no limit on the number of LOB output arguments that can be defined
for each stored procedure or function.

In Oracle 10g, the maximum size of LOB datatypes has been
increased from 4 gigabytes minus 1 to 4 gigabytes minus 1 multiplied by
the block size of the database. For a database with a block size of 32K,
the maximum size is 128 terabytes.