Beginners should start with short Leash Extension to gain experience with your flight area. It is easy to misgauge distances and allow your bird to land on a tree limb or roof that is out of reach. Many birds that are learning to fly are able to fly up but afraid to fly down from high perches.
Leash Extensions are made from high quality nylon and rubber shock cords that expand as much as 100% depending upon the health and strength of your friend.
Do not connect multiple extensions together. The connection can become snagged on grass making it difficult for a bird to maintain flight. Mow grass short to eliminate as much drag as possible when flying.