TL;dr= I would suggest buying this one of the options listed..
For those trying to compare all the options on these offered at the same time; here is the best I could do:
$49.99
iPower 4 Inch 190 CFM Inline HVAC Vent Blower Fan with 4" Air Carbon Filter 25 Feet Ducting Combo Set for Grow Tent Ventilation, Silver
(1) x 4 inches 190 CFM Inline Duct Ventilation Fan
(1) x 4 inches Air Carbon Filter
(1) x 4 inches 25 feet Ducting with 2 Clamps
No hangers
No controller
$59.99
Clearance
iPower Grow Tent Ventilation 4-in. 190 CFM Inline Fan Carbon Filter Ventilation Combo w/ Variable Speed Controller & 8-ft. Rope Hanger
(1) Pack Inline Fan
(1) Pack Carbon Filter
(1) Pack Speed Controller
(1) Pair Rope Hanger
No ducting
$59.99
iPower 4-in. 190 CFM Inline Fan + Carbon Filter + 8-Foot Ducting Combo w/ Variable Speed Controller & Rope Hanger for Grow Tent Ventilation, 4" Fan & Filter, Grey
4 Inch 190 CFM Duct Inline Fan Blower
4 Inch 1050+ IAV Australia Charcoal Filter
4 Inch 8 Feet Uninsulated Aluminum Ducting + 2 Stainless Clamps
One control switch for 3 settings
1-Pair 1/8 Inch 8-Feet Long Rope Hangers
$69.99
iPower GLFANXINL4FILT4MD8C 4Inch High CFM Inline Exhausting Fan & Carbon Air Filter w/1050+ IAV Australia Virgin Charcoal,Pre-Filter Included,Reversible Flange & 8Feet Ducting w/2Clamps Combo
4" 1050+ IAV Australia Charcoal Filter
4" 190 CFM Ducting Inline Fan Blower. Made with quality UL components for quiet operation.
8-Feet Uninsulated Aluminum Ducting w/ pair of clamps
No hangers
No controller