Search for K2 is a plugin for k2 very simple and intuitive to use.
Search for K2 need to do a search of the articles in the frontend of k2.
Once installed, the plugin will have to specify the custom form created in k2, which will be shown in the frontend into the search form.
Once you activate the plugin in the frontend we can go into a view of k2 with a list of items, we will see at the top of the search engine already running immediately.
For any doubt or question please feel free to contact me!