hi folks--just a heads up. i just found out recently that advancer now has a shelf size that fits the L and L liberty belle kiln (15"). DH gave them to me FOR MY BIRTHDAY!!!! they were out of stock at the time but they must have them in now because i received them today. so if you have a kiln that takes 15 in. shelves, there is now an advancer option for you! there was a little price break on them--don't remember how much it was. if you haven't ordered from them they are very nice and super communicative and helpful.