Small Butterfly K18 Earrings The round plate of the post and the butterfly are made of thin sheet metal. Length: Approximately 1.6cm Butterfly size: Approximately 4 x 5mm Post thickness: Approximately 0.7mm Post length: Approximately 9mm K18 hallmark is only on the catch. In the past, some posts did not have a hallmark. You can only judge by the photos and the construction. Please refrain from purchasing if you have any concerns. K18 catches tend to loosen and are easily lost, so it is recommended to replace them with the recent silicone type. (It is best to keep the catches safe.) Weight measurements are approximate. Errors may occur depending on the scale. Returns and exchanges are not accepted under any circumstances to prevent substitution, so please consider this before purchasing. Price negotiations are not possible. Shipped via Yu-packet mini.