What does "1.2m" (4 feet) mean?
Now there are many single beds on the market, so there are many sizes for single beds. If they are not made to order, there is little difference in size.
1.2m (4 feet =1.2192 meters) is a standard size for a single bed, usually 1.2*2.0m of the inner diameter and about 2130*1330*1180mm of the outer diameter.
