Using Telerik extension in plugin

I include Telerik.Web.Mvc.dll in my plugin and add into web.config this code

<configuration>
   <system.web>
        <pages>
            <namespaces>
                <add namespace="Telerik.Web.Mvc.UI" />
            </namespaces>
        </pages>
        <httpHandlers>
            <add verb="GET,HEAD" path="asset.axd" validate="false" type="Telerik.Web.Mvc.WebAssetHttpHandler, Telerik.Web.Mvc" />
        </httpHandlers>
   </system.web>
   <system.webServer>
        <validation validateIntegratedModeConfiguration="false" />
        <handlers>
            <remove name="asset" />
            <add name="asset" preCondition="integratedMode" verb="GET,HEAD" path="asset.axd" type="Telerik.Web.Mvc.WebAssetHttpHandler, Telerik.Web.Mvc" />
        </handlers>
    </system.webServer>
</configuration>

But in View i don't see this extension. What can I do to plug-in works?