Here is an example of what they are.
https://www.amazon.com/Weilan-Pheasant-Blinders-Spectacles-Anti-Pecking/dp/B07GN8GKZC/ref=sr_1_5?crid=ZNXDKROZ3PS6&keywords=pinless%2Bpeepers%2Bfor%2Bchickens&qid=1663774073&sprefix=pinless%2Bpeepers%2Caps%2C4054&sr=8-5&th=1