**IMPORTANT**PLEASE READ THE DESCRIPTION VIEW THE PHOTO ATTACHED TO THE LENGTH YOU DESIRE FOR THE PREMIUM NECKLACES--THESE ARE ALL UNIQUE. For the PREMIUM ONLY, the photo on the desired length will be the actual item you receive. They vary from approx. 9-10 mm on the 18"-20" Premium. Shells on the ends may be slightly smaller. The natural varieties are approx. 18" 20" or 24" in length and the shells on most are in the 9-11 MM size. If you would like to see what you will receive for these, please ask and we?ll send a photo. We string these here on Maui with real puka shells sourced from the Philippines, so no two are alike. The photo you see on your selection is the actual item you will receive. They are priced by the quality of the shells. Twist-Barrel Lock. If we have shells available, will also customize these to longer lengths for an additional $13 per inch added. The word "puka" means "hole" in the Hawaiian language, which in the case of these necklaces refers to the naturally occurring hole that is found in pieces of shells. Packaged in a drawstring pouch for giving. Could also be taken apart to use shells for other craft projects. If you don't see what you're looking for here, please ask, we have many other styles, colors and shell leis and bracelets available. If you need larger quantities, please ask.ease ask.