Valyria Stainless Steel Slide-On Pet ID Tags Material:Stainless Steel;features:durable and fadeless Length:6cm(2 3/8");Width:1.6cm( 5/8");Thickness:1.5mm;Hole Size:1.2cmx6mm( 4/8"x 6mm); Comes with a beautiful black Velvet Gift Bag Great slider pet ID tags for engraving personalized information,such as phone number,name,address,or any favorite patterns and text This tag slides onto single thickness nylon collars with metal buckles.This tag will not slide onto an adjustable collar with plastic snaps. Collar is not included.