Seems very durable and of good quality. Attaching them to a house is a bit of a chore to make sure they are lined up, which is why I gave this 4 rather than 5 stars. Here's what I did:
1. Attached the threaded "spikes" to the numbers.
2. Used a sheet of graph paper and held each number over the grid where I wanted it and then pushed the spikes through the paper.
3. Held the paper up to the house where I wanted the numbers and marked where each hole was with a pencil.
4. Removed the paper and drilled the holes for the plastic anchors.
5. Pushed the plastic anchors in to the holes.
6. Pushed the numbers' spikes into the plastic anchors.