These chunks are the real McCoy and have been cut from the staves of aged Whisky barrels that have come to the end of their  useful life which can be anything from 5 - 25 years, or maybe longer. 
The combination of Whisky and Oak gives you the timeless classic aroma of aged Whisky mixed with the fantastic flavour of Oak which is fantastic for Beef, Chicken, Lamb, Pork, Cheese or Vegetables.