Ordered both sizes for our bedrooms. Found the larger 53cm fit well in the larger, double room, while the smaller one fit perfectly in a single room. Had them professionally installed as the electricals were run in a switch loop and this didn't have the same connection points. Minus one star as it would be great if this came with a defuser; using a 10W LED blub (like 75W lumen), so  the bare light bulb is quite harsh and very easy to see. BUT, the light spread is very good in the room and does the job! Reasonable in price too.