12-spear with upper plate.
16-spear with lateral plate.
18-spear with half-ring, untreated.
Cross-blade 18-spear with half-ring, untreated.
Driven in with the use of a mallet or impact-tool (pneumatic hammer, post driver, etc.).
After driving in the anchor, pivot the spear clockwise by ninety degrees. The two blades fold out and become locked on the retention cleats.