I bought it yesterday. First impressions regarding the construction, positive. It is all solid metal, (the cheaper and colorful series of zovii are made of aluminum, except for the fire and the shackle of the lock which are obviously steel). It seems sturdy. I put the battery in, after first removing the alarm kit (which seemed a bit fake to me) and did sensitivity tests. I would probably like it to be a little more sensitive, (I couldn't find a sensitivity sensor), the lock needs to be shaken well for the alarm to work. That's why I didn't give it 5 stars. They might do this to avoid false alarms. I have seen much cheaper disc locks that are more sensitive. You can lock it on the disc without the alarm, as a simple padlock. Anyway, I will come back after some period of use and reevaluate.