Thank you for viewing. This is a set of two blue security alarms. Please refer to the attached photos for the size, how to use it, etc. Although it is new and unused, in the unlikely event that I send you the wrong item, or an item with scratches or stains that make it seem not new due to my mistake, I will accept returns and cancellations. It will be shipped via mail service. It will be delivered to your mailbox within 2-7 days from the shipping date.