The pens vary in weight depending on size and height as follows:
Small - 37 lbs
Medium - 45 lbs
Large - 51 lbs
Small - 48 lbs
Medium - 55 lbs
Large – 65 lbs
Box Dimensions (it is important, for shipping cost, that the middle dimension is under 30" so don't round it up :))
27 – 32 x 29.8 x 8
36 – 40 x 29.5 x 8
They are made for small to medium breed pups weighing up to 40lbs. They do not tip over because of the weight of the pen 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 pup is very stressed or aggressively trying to break out of the pen, we do not recommend using the product.
Here is our assembly video, which is very helpful in giving a "feel" for the pen.