Nice sturdy, 4 lb hook, can be used with the "Command Outdoor Clear Large Strips", (one extra strip is supplied and refills are available). The instructions indicate, "ONLY USE ON WINDOWS. Failure to follow instructions carefully may cause damage."  The design of the hook is simple and transparent, however it does allow water, moisture etc. to collect in the hollow base of the hook. This limits the use of the hook to windows under covered outdoor areas such as porches or overhangs. Still, the hook has a hefty 4 lb weight limit, and an inconspicuous appearance.