When evaluating a hand manual stacker, you must prioritize the Rated Load Capacity (typically ranging from 500kg to 2000kg) and the Maximum Lifting Height. It is crucial to check the Load Center Distance, as the capacity decreases as the load center moves further from the fork carriage. Additionally, ensure the Fork Width and Length are compatible with your specific pallet types (e.g., Euro vs. US pallets). Look for C-channel steel construction in the mast for superior rigidity and high-quality hydraulic seals to prevent oil leakage over long-term use.