**Advantages**:
1. Stackable units enable efficient use of space.
2. Mobile design allows for easy transportation of tools.
3. Rugged construction provides durability.
4. Multiple compartments facilitate tool organization.
5. Large storage capacity can accommodate various tool sizes.
Disadvantages:
Mobility might affect the stability of stacked units.
Heavy weight when filled with tools could make it harder to move.
Plastic components may not withstand extreme conditions.
Larger tools might not fit in some compartments.
Common Issues and Solutions:
Issue: Difficulty in locking the units together.
Solution: Ensure that both tiers align correctly before attempting to lock. Clear any debris or obstructions from the locking mechanism.
Issue: Wheels not rolling smoothly.
Solution: Regularly check for any obstructions or debris caught in the wheels. Consider applying lubricant if necessary.
Issue: Difficulty in opening or closing compartments due to stiffness.
Solution: Clean the tracks and edges of the compartments. Apply a silicone-based lubricant to ease the sliding mechanism.
