The closure is an inside lock that is removed with the key when opening. 2 keys are supplied. The A-ring comes in a new curve. A-ring approx. 50x45mm or of your choice It adapts much better to the man's anatomy. It is a very robust model with a material thickness of 3-4 mm. The inside diameter of the cage is approx. 33mm. The length is approx.: 25-55mm. The material is stainless steel. The total weight is approx.: 235 grams.