Ultimate Floating or Submersible Stock Tank De-Icer is safe in all stock tanks! Can be used as a floating de-icer with built in cage guard or in seconds converts to a submersible de-icer. Cord safety clip included which secures the de-icer to the edge of the stock tank, bucket or container to help prevent chewing, cribbing or removal of the de-icer. Convenient zone chart easily helps you choose the correct de-icer for your needs. Two year limited warranty. Automatically turns on at 43 degrees.