# \[Marlin] M200 - Set Filament Diameter

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**📅Update: 2020/09/18**
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## Description

Set the filament's current diameter and enable volumetric extrusion.

In volumetric extrusion mode the E axis specifies cubic mm instead of linear mm, and the firmware calculates how much length to extrude for the given volume based on the filament diameter.

## Usage

`M200` `[D<diameter>]` `[T<index>]`

### Parameters

* `[D<|>]` Detailed information (requires `M114_DETAIL`)

## Examples

A common diameter close to 3mm:

```
M200 D2.85
```

Turn off volumetric extrusion

```
M200 D0
M200 D  ; also works
```


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