Parametric Transformer is a gadget that you obtain by completing the quest Tianqiu Treasure Trail Quest Guide, and it can be used once per week to earn some, presumably random, rewards.
Using the item
To use the item, open up your inventory and select the Parametric Transformer gadget in the gadget section, then select "Place".
The item will then be placed in your current location, and you can interact with the device.
If you place it wrong, or decide not to use it yet, simply go to your inventory again and select "Retrieve"
Interacting with the Parametric Transformer lets you put in a total of 150 items to begin the process, and you can only put in materials that are dropped by monsters. Based on the game's description in the tutorials, the items that you get seems to depend on the materials used. Rewards outcome aren't very clear yet, or if rarity of the materials used even matters.
After putting in the materials, you will need to give some energy to the gadget by using elemental attacks until it reaches 100%. Completing this process for the first time will give you the "Transformation Nuclide" achievement in Wonders of the World section.
Rewards obtained after putting in 150 Ominous Mask: