This semi-solid block of odour neutralizing agent slowly releases ona to eliminate any airborne odours. Take the ona odour block out of the container and place in the area where odours lurk. The duration of the ona odour block will vary from 15-30 days relative to the airflow around the block and the ambient temperature. To reduce the strength of the block, poke holes in the cover and replace on the container. This will also prolong the life of the block.