These are SCX Digital System Standard Curve Borders with Barriers from TecniToys. Suitable for Ages 8 & Older. FEATURES: Multi-colored molded plastic 1.25" high barriers A new connecting system that provides quick and easy assembly Track can be used as either analog or digital with the use of the conversion track (SCXW2115) Digital cars can only be used on the new SCX universal track system Using digital cars on any other type track (CX black track) may cause damage to both cars and track INCLUDES: Four Standard Curve Borders with Barriers REQUIRES: SCX® Digital System Products SPECS: Scale: 1/32 COMMENTS: The SCX® Digital System products are not compatible with the other SCX® products. All SCX® Digital System products are marked with a special "X" symbol to identify them and to distinguish them from other SCX® products. tlc 11/30/12