These are basic clear plastic safety glasses that are comfortable to wear and provide excellent protection. They have large solid arms with vents that provide additional protection but also help prevent fogging. This also makes these glasses very strong and durable. The end of the arms have holes for attaching a cord so they can be worn around the neck until required. They can be used as an overglass for people who are already wearing prescription glasses and are sold singularly or come in boxes of 10.