This High Quality 7 Year Vinyl Sticker, Will Stick To Almost Any Size Letterbox, Its Clear Bold Text Is Highly Visible From A Distance To Alert Any Door To Door Canvassers From Posting Unwanted Junk Mail Through My Door. This May Be By Far The Best No Junk Mail Sign Available In The UK To Date. I Bought Mine From www.no-junk-mail.co.uk.