Dog tags pendants are made of soft, flexible silicone and come in 5 different colours. Pendants measure 28mm by 48mm and are roughly 6mm thick at the thickest point. You can mix and match any combination of two colours to make the necklace your own! All dog tags come on plain black cord with a breakaway clasp for safety. This item is not suitable for heavy biting, it is designed for mouthing, sucking or light chewing. Only suitable for children aged 3+ (strangulation hazard). The lanyard clip is not suitable for chewing, if you feel it is likely the clip will be chewed, the item will not be suitable.Please ensure use of the Oojamabob is under adult supervision. Although the pendants are fairly durable, they are by no means indestructible. Pendants will show signs of wear and tear eventually and may need replacing in time. Some may find that their pendant lasts for many many months without needing to be replaced and others may become damaged very quickly. This is entirely dependant on the intensity and frequency of the individual's chewing behaviours and unfortunately it is not possible to guarantee the length of time any individual pendant will last. If you are unsure which pendant will be suitable for your needs, please do contact me and I will help you to make a selection, as some are stronger than others. Please understand this is not an exact science and sometimes it may just be a matter of trial and error to find the right chew!