HARRINGTON'S SMRQ SERIES DUAL SPEED (VFD CONTROL) MOTORIZED TROLLEY ADDS POWERED MOBILITY TO OUR SEQ SERIES SINGLE-PHASE DUAL SPEED (VFD CONTROL) ELECTRIC CHAIN HOISTS FOR APPLICATIONS WHERE LONG TRAVEL DISTANCE IS NEEDED. RECOMMENDED OPERATING CONDITIONS FOR -4° TO +104°F AND HUMIDITY OF 85 OR LESS. STANDARD FLANGE WIDTH INCHES OF 2.28-6.02; OPTIONAL 6.03-12.00; 30/10-MINUTE DUTY RATING/H4.