... jack lift; Safely self locking, Positioning Precision, Heavy Duty, Uniform Lifting Speed, Low Efficiency, Use Infrequentl ... , RN-100 ton.* Safely self locking, Positioning Precision, Heavy Duty, Uniform Lifting Speed, Low Efficiency, Use Infrequently, Easy Installation ... availbale and fully synchronized.* Absolutely irreversible, they can support their applied loads without needing any brakes or other ...