dependencies {
  ....
  compile 'com.android.support:design:26.0.2'
  compile 'com.android.support:recyclerview-v7:26.0.2'
  ....
}

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  app:layout_behavior="@string/appbar_scrolling_view_behavior"
  tools:context="com.shaishavgandhi.fastscrolling.MainActivity"
  tools:showIn="@layout/activity_main">


 <android.support.v7.widget.RecyclerView
  android:id="@+id/recyclerView"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  app:fastScrollEnabled="true"
  app:fastScrollHorizontalThumbDrawable="@drawable/thumb_drawable"
  app:fastScrollHorizontalTrackDrawable="@drawable/line_drawable"
  app:fastScrollVerticalThumbDrawable="@drawable/thumb_drawable"
  app:fastScrollVerticalTrackDrawable="@drawable/line_drawable">

 </android.support.v7.widget.RecyclerView>

</android.support.constraint.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item
    android:state_pressed="true"
    android:drawable="@drawable/line"/>

  <item
    android:drawable="@drawable/line"/>
</selector>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

  <solid android:color="@android:color/darker_gray" />

  <padding
    android:top="10dp"
    android:left="10dp"
    android:right="10dp"
    android:bottom="10dp"/>
</shape>

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item
    android:state_pressed="true"
    android:drawable="@drawable/thumb"/>

  <item
    android:drawable="@drawable/thumb"/>
</selector>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

  <corners
    android:topLeftRadius="44dp"
    android:topRightRadius="44dp"
    android:bottomLeftRadius="44dp" />

  <padding
    android:paddingLeft="22dp"
    android:paddingRight="22dp" />

  <solid android:color="@color/colorPrimaryDark" />

</shape>