The Lucidium Pens are made for small to medium breed pups weighing up to 40lbs. They are not recommended for any pet that is aggressively trying to get out of the pen.
The pens do not tip over due to the weight and the rigid frame, however, the acrylic wall panels may break under excessive force. Therefore, we have a recommended weight limit of 40lbs. If your pet is very stressed, aggressively trying to break out of the pen, or even aggressively rough housing and smashing into the walls, we do not recommend using the product regardless of the pups size or weight.
The video below demonstrates the rigidity of the assembled pen.