They are also known as the black truss markings. They provide a quick visual for the tape user and speed up the measuring process. Originally, 19.2 inches was used in metric layouts. Dividing 5 into 96 inches (8 feet) gives 19.2 inches, which yields five trusses per sheet. The black arrow in the photo to the right points directly at the black diamond located on 19.2. The red stud markings every 16 inches allow for a standard layout of six studs per 8-foot (96) section.
1 Minors under 18 must be accompanied by an adult at all times in the range and store. 2  You must be 21 years old to shoot a handgun & 18 years old to shoot a long gun without being accompanied by a parent or legal guardian.
In Massachusetts, it is illegal for children under eighteen to have a BB gun or air rifle in any public area, unless: (a) an adult is with them; (b) they have a sporting or hunting license with them; or (c) they have a permit from the police chief in the town where they live. Even if children can use BB guns in your state or town, it is important that they be trained to use them safely and under adult supervision. 2  Never use a BB gun if you have been drinking alcohol or under the influence of drugs.