# Centralizer

> The centralizers optional block of a .well file: a list of Centralizer objects.

Property `centralizers` of the .well root, an array of objects, optional. [Defined in the spec](/format/spec/v2/object-schemas#centralizer--centralizers-since-v21).

| Field | Type | Required | Values / constraints | Description |
| --- | --- | --- | --- | --- |
| `from` | number | yes |  |  |
| `to` | number | yes |  |  |
| `spacing` | number | no | > 0 |  |
| `type` | string | yes |  |  |
| `diameter` | number | no |  |  |
| `description` | string | no |  |  |