Zip High Performance Block Firelighters contain unique energy granules which allow them to burn much hotter for longer compared to other competitor products Formulated to light even the most difficult fuels such as hard , smokeless coal or damp wood Each cube burns for up to 18 minutes (up to double that of competitor products), making them very powerful and enabling you to reliably light your fire first time, every time, leaving you more time to enjoy a warm cosy fire