<https://thebrewhut.com/product/oetiker-clamp-21-0-13-16/#webpage>
<http://schema.org/description>
"Oetiker® Stainless Steel Stepless® Clamps Stepless®... when nothing less than a perfect seal will do. Oetiker No. 21.0 Range Closed-Open: .701 - .827"
<https://thebrewhut.com/product/oetiker-clamp-21-0-13-16/>