These Mosquito-Thwarting Gadgets Have Been Wirecutter Favorites for 5 Years. (No Citronella Here.)

After spending 70 hours researching a category full of marketing hype and debunked methods, we found that the Thermacell products stand out by actually working. We recommend four different Thermacell products in our guide to the best mosquito-control gear for your patio or yard—two for home use and two that are better suited for camping or hunting.

Thermacell makes devices that work like diffusers, using heat to vaporize a small amount of insecticide into the air to create a bug-free zone. The active chemical is either metofluthrin or allethrin, which in numerous studies have proved to be effective spatial repellents for mosquitoes. They have both undergone thorough vetting by the Environmental Protection Agency and other regulatory agencies around the world and are deemed safe for this intended use.

Our testing confirmed the company’s claim that the Thermacell E90 Rechargeable Mosquito Repellent protects just over 300 square feet (about a 20-foot-diameter circle) in still conditions. The E90’s simple interface and rechargeable lithium-ion battery (with nine hours of battery life) make this repellent convenient and easy to use. The E90 comes with a 12-hour repellent cartridge, but 40-hour cartridges are also available.

The Thermacell LIV Smart Mosquito Repellent System is a substantially bigger investment toward larger-space coverage. It consists of three, four, or five diffusers that look like high-end landscape lights. The devices are connected to an app that provides total control over the system, including turning the diffusers on and off, putting them on a schedule or a timer, checking the amount of repellent remaining, and even changing the color of the little lights on the units. It can also be connected to a smart-home system.

Internally, the EX90 is identical to the E90, but the EX90 has a more compact design, rubbery grip areas on the sides, a lanyard and carabiner (to hang it from a branch), and a locking lid (the E90’s lid is held in place with magnets). The EX90 costs the same as the E90, so the choice is really a matter of whether you think you’ll need the added durability of the EX90.

We really recommend this model only if you need something even more rugged and durable for long camping trips. The MR450 runs on a butane cartridge, which is faster to burn through and harder to replace than simply recharging a battery. This model also uses four-hour repellent pads, which last for far less time than repellent cartridges, and it’s harder to tell when they’re used up.

Don’t expect your Thermacell to work the moment you turn it on. You need to turn it on about 10 to 15 minutes before you plan to be outside, to allow the repellent to “saturate” an area.

It won’t work in windy conditions. Thermacells are all about building up an area of protection around the diffuser, so it just takes one good breeze to blow it all away.

Also, be careful when opening the repellent replacement cartridges. Some users have accidentally broken the cartridge wicks when they didn’t pull the cap straight up—and if the wick breaks, the cartridge no longer works.

A version of this post was originally published as part of our 2021 “52 Things We Love” series, an ode to Wirecutter picks that have withstood the test of time. Read the entire series. The latest version was edited by Annemarie Conte and Doug Mahoney.