Adjustable Perimeter: 7 inch – 9.5 inch . It can be adjust by the braided rope and match for a male or female. The lava beads work well with absorbing your favorite Essential Oils. The pores will trap and slowly diffuse the oil well throughout the day for added benefits. You do not get oil on your skin when you wear it. Howlite is a calming stone that helps relieve stress and aid with insomnia. Lava Stones.The bracelets is made by original stone, We can’t guarantee that every stone is round enough, but most of them are. It would make a gift as it also comes in a gift bag.