Dear Slowpoke-sama, The detachable collar is finished. The neck circumference is 42cm, but since it's knitted, it will stretch a bit, and it can be adjusted with the ties. Thank you. Neck circumference: 42cm (Adjustable with tie strings) Tie strings: 24cm Made with 100% acrylic yarn. For dogs, cats, and stuffed animals too! This is a handmade item by an amateur. Please consider this with understanding. #HalloweenOnMercari