Grobag sleeping bags have answered my prayers in terms of keeping the covers on my son when he wants to kick them off. Available in a number of different weights (tog) they also come with a room thermometer which gives guidance on how your baby should be dressed, at that temperature, in the particularly weight grobag. This is very helpful to a first time mum like me, worried about baby overheating (but not wanting baby to be cold!). The grobags come with a popper on the arm holes so that you can adjust them for smaller babies.
I have found grobags to be perfect for my little boy. They now form part of his bed time routine, with his last feed taken in his grobag. They provide continuity when you're away from home, helping baby settle. The sleeping bag design ensures that baby does not wake himself by kicking off all the covers.
Highly recommended - 5 stars.