You are going to want to get a lock for your unit that is not easily broken off by bolt cutters or a sledge hammer. The best lock to get is a disc lock that can be purchased at most hardware stores. Whatever you do don’t ever give your security number or keys to anybody else, a lot people will give there security number and there key to someone they trust, I can understand trusting someone but this day and age you never know. But let’s say you do trust this person with no doubt in your mind, maybe be they would never steal from you but it still is possible of them to lose the key, maybe it might be your last spare key, what a headache. What if your buddy or family member gets to the gate and the security guard will not let them in, well now you have to go to the storage facility anyway, waste of time. You should also try not to take anybody you don’t know very well to your storage unit, if they see something they like sometimes all the security in the world can’t keep people out, the old saying goes “if there’s a will there’s a way”. One last thing you should do is make sure if you have any crazy ex-wife’s or husband or anybody you know might like to get something out of your unit without your permission make sure to alert the storage companies’ manager and make sure the storage company is aware of the situation.