Size is approx; 10 by 10 by 10cmAdditional product info; Shoulder Strap With Acrylic Charm!It comes in colors that match the image of Pokmon.Compatible Smartphone Case Shape- Usable: Central bottom opening of at least 12mm- Not Usable: Entire bottom openAttachment Method1. Set the strap sheet in the smartphone case and take the tongue of the sheet out from the case.2. Attach the smartphone to the case.3. Attach the carabiner to the bottom of the sheet.