My 3 year old has just learnt to open our lindam stair gate. He has GDD (about 18-20 months behind) as well as some other problems and I desperately need something not too expensive that will keep him safe. I've been looking at this site clicky link but not sure if I need extra tall or something with a Houdini proof lock. He's just over 90cm tall at the moment but I can imagine I'll still be needing a gate when he's quite a bit taller.