I know the Roverpet Small Durable Puppy Rails are designed for PVC Whelping Box.
Firstly they fit snugly and securely inside the Whelping Boxes which reduces the risk of harm. In addition the durable pig rails should be up higher than pups up until they are 3 weeks of age. Therefore they are available in white, which gives them the modern look and feel. I would say the pig rails are used to protect the puppies should mom roll over and accidentally smother them. Firstly when puppies are of sufficient size, rails can be removed to increase internal whelping space. Fits 2′ wide x 2′ long Puppy Pen.
Besides the Roverpet pet rail assemblies are made from tough and sturdy PVC plastic. For instance multiple size “legs” allows the breeder to vary the rail height as appropriate for dog breed size. I know the pet rail is to help keep the puppy from being smashed between its mother dog and the sides. Therefore this system will help prevent canine from laying or stepping on the puppies. (No Tools or Glue Needed to Assemble)
For example newborn puppies are very vulnerable to being smothered, plastic pet rails help prevent this. Emphasis on easy to clean with soap and water. I know the small PVC durable puppy dog rail, is placed just above the floor to protect them from being suffocated. Therefore the puppies will stay in a safe and warm area when using sturdy plastic pig rail system. Best of all the Roverpet pet products are made in the USA. Firstly: Small Pig Rails can reduce the risk of possible suffocation.
Items Included: #22PR
(2) #PR24LB PVC tubular pipe w/pre drilled holes for legs
(2) #PR24CB PVC tubular pipe for cross bar
(4) PVC support legs (please note height with order)