Super Sprouter� Perfect Plug� growing media replacement plugs are great for seed starting and cuttings. Perfect Plug� growing media plugs use a custom peat moss blend, with Mother Earth� BioChar added, exclusively developed for Super Sprouter� to allow a great mixture of moisture and aeration. Perfect Plug� media plugs have a pre-drilled dibble to foster the optimum environment for stem to media contact. If limiting your plastic waste is important to you, use these refill plugs to reload your Perfect Plug Tray� starter tray. Easy to use, just insert cutting or seeds into your plugs and watch them grow.