Our patented GroundBreaker Stake is designed to easily penetrate the earth with just a few swings to provide a sturdy foundation for your mailbox, address marker, or real estate sign post that installs in seconds. The blue steel stake is twenty eight inches long in total. Nineteen inches go below ground, with nine inches left above ground which will accommodate our 4x4 vinyl post for a snug, secure fit that will not rattle or blow in the wind.