I'm using a drawable for seekbar thumb with 

```
android:thumb="@drawable/thumb"

```

How can I set the size of this thumb in **dip** unit? Because I use a style for seekbar like 

```
<style name="CustomSeekBar">
    <item name="android:indeterminateOnly">false</item>
    <item name="android:minHeight">8dip</item>
    <item name="android:maxHeight">8dip</item>
    <item name="android:thumbOffset">8dip</item>
</style> 

```

and I want to have the thumb with `12dip` height and width.