Permanently Locking Sparkly Ring Day Collar, a delicate and discreet day collar with 22 cubic zirconia crystals Simple measuring guide available here This day collar has a locking link in place of a traditional clasp, allowing it to be permanently closed. See guide for instructions on how to close and lock the link. Once it is locked the only way to remove the collar is to cut it off, in an emergency a pair of sturdy nail clippers will cut through either the chain or the locking link itself Materials: 925 Sterling silverDimensions:Ring – 18mm in diameter and 4mm thickChain link size - 1.7x2mm (Belcher).Your necklace will be sent in the presentation gift box shown in the photographs, ideal for safe storage or as gift.Shown against a standard sized business card (55x85mm) for scale.