Moulded to Langstroth standard dimensions, has migratory vents, allocation for spring clips. 
The reinforced ribbing on the side of the lid gives added strength for strapping hives down tight.
The standard lid sits flush on top of your super allowing hives to be stacked hard up against one another.

The ribbed design gives the lid added strength, durability and is UV stable for 30+ years.
Nuplas plastic lids are also interchangeable with wooden hives.