The Seedmaster II Seeder has a thumb-operated dial that vibrates the seeds in the holder to slide down the trough one at a time. Four interchangeable baffles allow for precision sowing of a wide range of seed sizes. This tool saves valuable time and cuts down on thinning. This tool is handy for sowing in the garden, and also for plant seed trays indoors. It's not a tool you'll be using all year round, but when it comes to seed planting time, you'll be glad you picked the Seedmaster II. This seeder is 6cm wide, 5cm tall, and 23cm long.