Purchased this box as I moved into a house where the gas box door had been broken off from the case. The door itself is held on with pins into the housing, however the point at which the pins sit in the housing is very flimsy and had broken. The unit itself is made of three components 1. base – which attaches to the wall and the gas meter 2. housing 3. door Installing the base I would not attempt unless I was a gas engineer due to the nature of the work. However if like me, the door is broken or the housing then replacement of this is a 10 minute job. The housing is held onto the base with three plastic splay pins. Two at the top and one at the bottom of the housing. To remove, push the pins in from the outside and reverse to install. One niggle is that the box I believe is made of carbon fibre and holes where the pins attached have been drilled. After working with the box I found that small shards of the glass where in my skin and every now and then it felt like I had splinters in my hand. Working with gloves would be my recommendation. Besides that the box is a standard unit.