# Dielectric Specular Node
## Description
Returns a **Dielectric Specular** F0 value for a physically based material. The material to use can be selected with the **Material** dropdown parameter on the [Node](Node.md).
A **Common** **Material** type defines a range between 0.034 and 0.048 sRGB values. The value between this range can be selected with the **Range** parameter. This **Material** type should be used for various materials such as plastics and fabrics.
You can use **Custom** material type to define your own physically based material value. The output value in this case is defined by its index of refraction. This can be set by the parameter **IOR**.
## Ports
| Name | Direction | Type | Binding | Description |
|:--- |:---|:---|:---|:---|
| Out | Output | Float | None | Output value |
## Controls
| Control | Description |
|:---|:---|
| **Material** | Selects the material value to output. The options are:<ul><li>**Common**</li><li>**RustedMetal**</li><li>**Water**</li><li>**Ice**</li><li>**Glass**</li><li>**Custom**</li></ul> |
| **Range** | Controls the output value for a **Common** material type. |
| **IOR** | Controls the index of refraction for a **Custom** material type. |
## Generated Code Example
The following example code represents one possible outcome of this node per **Material** mode.
**Common**
```
float _DielectricSpecular_Range = 0.5;
float _DielectricSpecular_Out = lerp(0.034, 0.048, _DielectricSpecular_Range);
```
**RustedMetal**
```
float _DielectricSpecular_Out = 0.030;
```
**Water**
```
float _DielectricSpecular_Out = 0.020;
```
**Ice**
```
float _DielectricSpecular_Out = 0.018;
```
**Glass**
```
float _DielectricSpecular_Out = 0.040;
```
**Custom**
```
float _DielectricSpecular_IOR = 1;
float _DielectricSpecular_Out = pow(_Node_IOR - 1, 2) / pow(_DielectricSpecular_IOR + 1, 2);
```