(Note) I think a chain of about 3.5mm will fit through the plate. Total length: approximately 11.3mm. Inside diameter of the maru-sen bail: approximately 3.8x1.7mm. This is a pendant frame for a 6mm round stone with a 6-prong claw setting. Because it's a pressed frame, no advanced skills are needed for claw setting. Craft enthusiasts should be able to set the stone easily. It's easier to set stones with less thickness, even for 6mm round stones. Some stones may not be able to be set. Please contact us if you would like to purchase multiple items.