Safety Pile Caps Be pleased with the white safety pile caps, they are designed exclusively to secure the top of your posts against sun damage and rainwater. They preserve the longevity of your post and prevent them from rusting. Robust and sturdy the superior PVC caps wont dry and won’t crack over time. Easy to fasten they fit on any 1-11/16 inch posts. No need to worry about anyone cutting themselves on the post’s edges, have your mind at ease and appreciate quality time on your deck! It is also a simple and effective way to add a more finished appearance to the overall look of your dock!