A frame barriers also known as control barriers are commonly used at many public events. They are frequently used at sporting events, parades, carnivals, political rallies and outdoor festivals. Event organisers, venue managers and security personnel use these barriers as part of their crowd management planning. Barriers act as a physical and psychological barrier, used to demarcate no access zones and to designate space for lines. They are also used by police to control large gatherings. These barriers are most commonly made from steel although lighter weight aluminium and plastic variations are sometimes used. Some barriers are constructed in such a way as to allow them to be locked together which can be an effective way of creating good impenetrable lines giving them the advantage of not toppling over as when single. A frame barriers often carry advertising media in the form of plastic or vinyl sheeting containing the advertiser’s logo and details of the product or business. These types of A frame barriers are more common at public functions such as fetes and sporting events.