A Metalbond reader has a steel cage available:

Dimensions are 48 inches long by 32 inches in height and 30 inches wide. It collapses into six pieces that can be placed under a bed or in a closet. Assembly is easy and takes about 15 minutes using a wrench. The cage is made up of 6 parts: top, bottom, front, back, right and left.

This cage is being given away for free, but you will have to pick it up yourself from a location in Rhode Island.

IF you are interested in this cage and you can genuinely use it, get in contact with me and I will put you in touch with owner of this cage. This is a genuine (and very generous!) offer, but it is not for someone who is going to sell this.

Only respond if you can genuinely use this yourself and can pick it up in person.

 UPDATE: The cage is spoken for.