To get it on them, or yourself, you'll need to choose your size. The ventilated cage locks to five possible base rings and spacer with tons of custom size options. Once you have the three interlocking pieces together, apply some water based lube and gently pull your testicles through the base ring before bending your (non-erect, please!) shaft into the cage. Lock up, and you're done!
A classic padlock and two keys are included - keep at least one of the keys in a very safe place, since the padlock isn't the type you can easily pick. As for that airport friendly point we made at the beginning, the Acrylic See-Thru Chastity Cage comes with six plastic lock tags that (probably) won't set off any alarms.
In body safe silicone, the Blueline Acrylic See-Thru is easy to clean using warm soapy water or a good toy care fluid/foam, but it can also be boiled or bleached (remove all plastic pieces first) for more thorough sterilization.
* The Blueline Acrylic See-Thru's shaft cage measures about 4.25"/4.66cm) long and 1.5"/10.8cm in inner diameter. Rings and spacers range in size to fit most.