This is honestly one of the best items we sell. With this patch you won't lose any more flies while walking through brush or even just knocking them off inadvertently, as is the case with a standard, open faced fly patch. The magnetic "fly catcher" is great for holding a fly while making a tippet change and the covered foam panel holds flies securely until you are ready to put them back in your fly boxes. Pin-on attachment. 3.6" x 2.6" x .7". Made in Japan.