What I like about these is that they are velcro so that the baby cant work its arms out and in one of them, I think the HAZO or ALZO or some such name (I bought one...lol) they have actual velcro arm straps inside the blanket almost like a straight jacket and the blanket is big enough for say a 15 to 18 pound baby. Plus all the zippers and such to get to the lower half...lol.
Reading that sounds strange I know...straight jackets on a baby. Hmmm...maybe thinking of future difficult child's!