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 $344.06The Mighty Mule MM371W is the better automatic gate opener overall, rated 3.3 to 3.2. The TOPENS A8131 wins on gate weight and gate length. The Mighty Mule MM371W costs $14.94 less ($344.06 vs $359).
A low cost opener for a heavy single gate near an outlet. Pick a UL 325 listed kit instead where the gate faces a public road or children.
Amazon $359Prices 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 TOPENS A8131 for gate weight (gates up to 880 lb per leaf vs gates up to 550 lb per leaf) and gate length (gates up to 18 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 | TOPENS A8131 |
|---|---|---|
| Overall rating | 3.3/5 | 3.2/5 |
| Gate weight 20% | 50 gates up to 550 lb per leaf | 89 gates up to 880 lb per leaf |
| Gate length 15% | 60 gates up to 16 ft per leaf | 80 gates up to 18 ft per leaf |
| Safety listing 15% | 100 UL 325 listed | 0 no UL 325 listing published, scored as none |
| Price 25% | 75 $344.06 | 72 $359 |
| Warranty 25% | 0 1-year warranty | 0 1-year warranty |
Specifications
| Mighty Mule MM371W | TOPENS A8131 | |
|---|---|---|
| Gate | ||
| Gate type | Single swing | Single swing |
| Heaviest gate | 550 lb | 880 lb |
| Longest gate | 16 ft | 18 ft |
| Time to open | 14 s | 15 s |
| UL 325 listed | Yes | - |
| Power | ||
| Power | Battery, solar ready | Battery, solar ready |
| Motor voltage | 12 V | 24 V |
| Build | ||
| Remotes included | 1 | 2 |
| Weight | 23 lb | 24.5 lb |
| Warranty | 1 year | 1 year |
