Does anyone recognize this unit? My best guess is that it's a ceiling light used in appartement stores?

I have bought it recently in a second hand shop.

Dimensions WxLxH: 63x 63x 6,5 cm
Material: steel and plastic (nylon)
Electronics: Craft Balast LPF (Belgium).

Can anyone tell me which year this unit dates back to?

Thanks!

Ruben