I needed to buy the spikes for a private home to position on the parapet at the top of the house. The spikes arrived safely and promptly. The special adhesive worked perfectly and I was able to attach them without a hitch. For weeks after the spikes were in position whilst the scaffolding still allowed observation, there was no evidence of any birds landing and fouling on the stonework. Incidentally, when I found out that I was one spike short, the company waived the full price of packaging and only charged a reasonable fee. I would use the product and company again without hesitation.