My4Sons M4 Agitator
The M4 with a built-in agitator, for anyone spraying powders or mixes that settle in the tank.
Amazon $299.99$299.99
The My4Sons M4 Agitator is the better battery backpack sprayer overall, rated 3.7 to 2.6. The My4Sons M4 Agitator leads on runtime or airflow, value and features. The My4Sons M4 Agitator costs $152.99 less ($299.99 vs $452.98).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Solo 442 18V
#16 in 4 gallons and upFull review
A commercial-style 18 V sprayer with set pressure steps and a gauge, for applicators who need repeatable rates more than a low price.
Amazon $452.98$452.98
Which should you buy?
- Choose the My4Sons M4 Agitator for runtime or airflow (50 tanks per charge (200 gal) vs 2.5 hours per charge), value ($75 per gallon of tank ($299.99, 4 gal) vs $113.25 per gallon of tank ($452.98, 4 gal)) and features (battery and charger included, adjustable pressure, 4 or more nozzles, metal wand, agitator vs battery and charger included, adjustable pressure, gauge or control panel).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 4 gallons and up battery backpack sprayer; a clear win is highlighted. How we rank explains each one.
| Factor weight | My4Sons M4 Agitator | Solo 442 18V |
|---|---|---|
| Overall rating | 3.7/5 | 2.6/5 |
| Value 25% | 30 $75 per gallon of tank ($299.99, 4 gal) | 4 $113.25 per gallon of tank ($452.98, 4 gal) |
| Tank size 10% | 67 4 gal tank | 67 4 gal tank |
| Spray power 20% | 71 up to 80 PSI | 50 up to 60 PSI |
| Runtime or airflow 20% | 100 50 tanks per charge (200 gal) | 21 2.5 hours per charge |
| Features 15% | 90 battery and charger included, adjustable pressure, 4 or more nozzles, metal wand, agitator | 60 battery and charger included, adjustable pressure, gauge or control panel |
| Warranty 10% | 0 warranty not published, scored as none | 0 warranty not published, scored as none |
Specifications
| My4Sons M4 Agitator | Solo 442 18V | |
|---|---|---|
| Spraying | ||
| Tank | 4 gal | 4 gal |
| Max pressure | 80 PSI | 60 PSI |
| Nozzles included | 9 | - |
| Wand length | 48 in | 20 in |
| Hose length | 60 in | 48 in |
| Power | ||
| Battery | 12 V 8 Ah, included | 18 V, included |
| Runtime per charge | 6 hours | 2.5 hours |
| Gallons per charge | 200 gal | - |
| Tanks per charge | 50 | - |
| Features | ||
| Adjustable pressure | Yes | Yes |
| Metal wand | Yes | No |
| Agitator | Yes | No |
| Gauge or control panel | No | Yes |