This plastic dust-cover keeps the hair from gathering around the bottom of the post.  It also protects the dogs feet from the concrete-anchors that stick up out of the ground.  This is a replacement part. The post-kit sold with the Signature Series includes this part.

Features:

• Keeps hair from gathering at the bottom of the post.
• Protects the concrete anchors.
• Reduces the likelihood of dogs getting injured on the concrete anchors.