Division Tech can be found in the Dark Zone and can be upgraded into crafting materials.
Standard Division Tech can be made into Specialized material for a 2 to 1 trade.
Specialized Division Tech can be made into a High-end material for a 2 to 1 trade.
High-end Division Tech is used for crafting items bought from Dark Zone level 50 blueprints and you need 3 for each item.
You can upgrade your Items at the Tech stage in your Base.