I was sent this kit to review and I have to say it's wonderful.  It is perfect for larger and heavier picture frames.  The 21" x 36" will hold up up to 16 lbs.  Also, this kit will work with sawtooth picture hangers as well as wire back picture hangers.  One of the great features of this kit is there are 16 photo and poster strips perfect for office, homeschool maps / murals, kitchen, bedroom or library.....all in all this is a must have for any home...lots of versatility and your walls remain free of marks and holes