The end clasps are made of silicone, hypoallergenic, reduces the risk of allergy and measure 4x4mm. They fit all kinds of studs, studs and earring hooks. - If you buy multiple items, don't forget to tell me ask for the total BEFORE paying by ebay or mail, because the reduction of shipping costs does not happen automatically, and the ebay cart is not working well. - Communication is very important on ebay, it allows you to avoid possible small worries, there is always a solution to every problem ;) The articles are packaged with care in sachets, bubble wrap if necessary, and taped in the envelope. Every order is important, big or small. My dear European customers and from all over the world, if you want a tracked shipment, please ask me by email, I will send you the invoice. I send with ple.