Request the information from your local forklift dealer that is an authorized dealer for a lift truck company. If you are an end user tthe OEM company will not give you the information. But remember not all basic capacity rated trucks will have the same net capacity rating at maximum lifting height. Forklifts are liek men & women they are all different - in spite of the rumors you hear.
So it is important you also ask what is both the basic lift capacity rating of the unit (important if physical size is important) and the net capacity at maximum lift height with any attachments required (i.e. side shifter, fork positioner, etc.)