The package consists of 3 models saved into single blend file. After unpacking the zip file you'll find the blend file named "Any Size Radiator Pack". Inside the object folder you'll find 3 basic models named: "1 Panel Radiator" "2 Panel Radiator" "3 Panel Radiator" Beside of this there are other equipment elements, like radiator blanc and valves, named (prefix "0"): "0 radiator blanc" "0 Radiator Flow Valve" "0 Radiator Return Valve" "0 Radiator Vent Valve" The rest of files are used by array modificator and you don't need to use them. You need to delete them from scene when the final object is ready. Because the model contains array modificator, I would recommend to append it as library element into your own scene. More detailed tutorial on how to use this pack in in the video attached: https://www.youtube.com/watch?v=114lI4KnLT8&t=331s The model is built in scale 1m = 1 Blender Unit. Only basic materials used, easy customizable for your own preference.