The closure is an internal lock which is removed when opened with the key. A lock with a pin is also possible where, for example: a disposable lock can also be attached. 2 keys are included. The curved A-ring is on the inside between the testicles and penis cage. The A-ring is of your choice. This model adapts very well to the man's anatomy and can be worn almost invisibly under clothing. Very robust model with a material thickness of 3-4 mm. The inner diameter of the cage is approx. 31-33mm. The size is approx.: 75x95x55mm. The material is stainless steel. The total weight is approx.: 380 grams.