This set includes 4 electric meters and 2 gas meters These are 3d resin printed, High detail models. But as resin is delicate, if they do break all you have to do is use thick super glue to put them together again - but I'm sure you already know that being an hobbiest like you are! The sprues are the smallest connecting points on the model and will break off easy, especially when warmed up. To help remove printing sprues wash part under hot water to warm it up.