This is the 2-3/4 inch giant spike, our largest spike we have. Each spike comes with a screw for fastening.

Screwback Spike description:
height: Two and 3/4 inches (70 mm)
base: 3/4 inch (19 mm)
color: silver nickle
base metal: aluminum
finish (plating): nickle
screw type: Size 1/4 inch - 20 NC Tap. 1/2 inch long.
shape: giant round tree-like spike
unit size: Bag of 100 spikes