This doesn't really answer your question, but we didn't bother with the bed rails. Our daughter moved to her toddler bed at 18 months and we just put a smaller cot mattress (from the cot we had in our room) on the floor next to her for about a week or two. Duvet or some pillows would work just as well. She was fine. She's actually only fallen out twice (in 2 months) but was fine, she got right back up in bed when I came in and went back to sleep. I think at most we might have used the bed rails for a month, but then taken them off, so would have been a waste of money. They work it out for themselves. Also, don't be scared about making the switch. It was really easy and she took to her new bed so well. She loves it and it really is her space now because she can get in and out and put her toys in to play if she wants. I think her sleep has only gotten better now that she has her bed.