The smaller of the two most common size of diecast model cars, the 1/43rd scale tends to lack some of the detail of it's larger brother but the one plus size is that you won't need to go out and get a new mortgage to buy a bigger house to display them in!
If you have children and you find the kids want to play with them you can also pick up decent looking Hotwheels cars for about £1 which will keep them away from your treasured collection!