Seed starter greenhouse kits, also known as seedling trays or propagation trays, are containers specifically designed for starting seeds indoors. These trays provide a convenient and organized way to germinate seeds and nurture seedlings until they are ready for transplanting into larger containers or outdoor gardens. 

Humidity Dome: The seed starter kit comes with a clear plastic dome or lid that fits over the top of the tray. This dome helps to create a mini greenhouse environment, trapping heat and moisture to promote seed germination. The dome can be removed once the seeds have sprouted.

Seed starter trays are an essential tool for gardeners who want to start seeds indoors or in a controlled environment. They provide an efficient and organized way to germinate seeds and grow healthy seedlings for transplanting into the garden.