The mod adds inserter modules that speed up hand crafting
Inserter-apprentice - opens after modular armor and accelerates crafting by 10%
Inserter-master - opens after power armor and accelerates crafting by 25%
Inserter-virtuoso - opens after the power armor mk2 and accelerates crafting by 50%
Inserter-champion (only with Krastorio2) - opens after power armor mk3 and accelerates crafting by 100%