Dear Customer,
This product contains 3 sets of Roof Top Access Ladders (12 pieces in total):
Models in Blender are measured in real life units (mm) as shown on one of attached referece picrures.
Files included contains also example configurations ready to use (You can of coarse make own combinations).
Models are fully unwrapped, so You can change textures for own easyly (my textures are also possible to download).
In my opinion the model is rather low poly, this means the smaller part has 3 736 verts (rooftop ladder), the most complex 10 226 (double ladder).
I attach also Blender file in case You wish to play with my modes.
BR,IG-n