# Reduction

> The reduction block of a .well file: a list of Reduction objects.

Property `reduction` of the .well root, an array of objects, required. [Defined in the spec](/format/spec/v2/object-schemas#reduction--reduction).

| Field | Type | Required | Values / constraints | Description |
| --- | --- | --- | --- | --- |
| `from` | number | yes |  |  |
| `to` | number | yes |  |  |
| `diam_from` | number | yes |  |  |
| `diam_to` | number | yes |  |  |
| `type` | string | yes |  |  |