Super Sprouter Perfect Plug replacement plugs are great for seed starting and cuttings. Perfect Plug uses 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 Plugs have a pre drilled dibble to foster the optimum environment for stem to media contact. If limiting your waste plastic is important to you, use these refill plugs to reload your Perfect Plug Tray. Easy to use, just insert cutting or seeds into your plugs and watch them grow.