Mighty Mule MM371W
#3 in Single swingFull review
The mainstream DIY choice for a medium single driveway gate, with a real UL 325 listing. Buy the battery with it and check the length and weight chart first.
Amazon $344.06$344.06
The Mighty Mule MM371W is the better automatic gate opener overall, rated 3.3 to 3.2. The Mighty Mule MM371W leads on price and gate weight. The US Automatic Sentry 300 wins on warranty and gate length. The Mighty Mule MM371W costs $1,050.94 less ($344.06 vs $1,395).
US Automatic Sentry 300
#5 in Single swingFull review
A commercial grade, UL 325 listed single gate opener with a long warranty for buyers who value proven parts support over capacity per dollar.
Amazon $1,395$1,395
Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Mighty Mule MM371W for price ($344.06 vs $1,395) and gate weight (gates up to 550 lb per leaf vs gates up to 400 lb per leaf).
- Choose the US Automatic Sentry 300 for warranty (3-year warranty vs 1-year warranty) and gate length (gates up to 20 ft per leaf vs gates up to 16 ft per leaf).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every single swing automatic gate opener; a clear win is highlighted. How we rank explains each one.
| Factor weight | Mighty Mule MM371W | US Automatic Sentry 300 |
|---|---|---|
| Overall rating | 3.3/5 | 3.2/5 |
| Gate weight 20% | 50 gates up to 550 lb per leaf | 24 gates up to 400 lb per leaf |
| Gate length 15% | 60 gates up to 16 ft per leaf | 100 gates up to 20 ft per leaf |
| Safety listing 15% | 100 UL 325 listed | 100 UL 325 listed |
| Price 25% | 75 $344.06 | 0 $1,395 |
| Warranty 25% | 0 1-year warranty | 50 3-year warranty |
Specifications
| Mighty Mule MM371W | US Automatic Sentry 300 | |
|---|---|---|
| Gate | ||
| Gate type | Single swing | Single swing |
| Heaviest gate | 550 lb | 400 lb |
| Longest gate | 16 ft | 20 ft |
| Time to open | 14 s | 16 s |
| UL 325 listed | Yes | Yes |
| Power | ||
| Power | Battery, solar ready | Battery, solar ready |
| Motor voltage | 12 V | 12 V |
| Build | ||
| Remotes included | 1 | 2 |
| Weight | 23 lb | - |
| Warranty | 1 year | 3 years |