title: not found Glass Development Kit at android Sdk manager
body: <p>i have read<br>
      <a href="https://developers.google.com/glass/develop/gdk/quick-start" rel="nofollow noreferrer">https://developers.google.com/glass/develop/gdk/quick-start</a></p>
  
  <p>We recommend installing the ADT Bundle for easier development. The rest of these steps assume you have this installed.
  Click Window > Android SDK Manager.
  Install the SDK Platform and Google GDK Sneak Peek for Android 4.0.3 (API 15). Everything else is optional.</p>
  
  <p>but at my  Sdk manger i cannot find it,i also update my Sdk manger,but also not found.
  <img src="https://i.stack.imgur.com/Rxtv7.png" alt="enter image description here"></p>