The home security industry has been dominated by big companies that provide whole-home security systems and 24/7 monitoring. If you wanted to go with a more DIY approach, the market was dominated by industry giants like Honeywell that produce nearly every home security device you can imagine.

While this model has worked for many years, home security startups with more focused product lines are now proving quite successful at challenging the traditional model of home security. The advantage of this new model is simple: not everyone wants or needs everything a full home security system can offer, and these startups are offering choices that put control back in the consumers’ hands.

A Massive Shift

It’s become very easy for consumers to adopt a DIY approach to home security with recent advances, including widely available Wi-Fi, smartphone apps, and greatly improved camera technology.

Additionally, smaller companies have an easier time adapting to the rapid pace of change in tech-related industries, and they tend to focus on doing one or two things extremely well—rather than trying to do everything for everyone like larger companies do. Individually, these startups are succeeding, and cumulatively, they are threatening the traditional home security industry model.

“You can really see these changes over the last year,” says David DeMille, home security expert with A Secure Life. “More companies than ever are unbundling services, reducing prices, and introducing smart features and integrations with third-party gadgets like Amazon Echo.” Situations like these are always great for the consumer—they force a shakeup of outdated models and prevent larger corporations from getting too entrenched and stale.

Home security startups are continuing to receive a lot of funding from venture capitalists eager to disrupt the industry. While there are dozens of such startups, these four are some of the best. Each has received over $40 million in equity funding and has seen success in their target market.

1. Ring

Ring produces a slick smart doorbell system that incorporates a camera and internet connectivity to allow you to see who’s at the door anytime, anywhere. Edward Chester of Trusted Reviews says it is “among the most well integrated and easy to use” video doorbells out there.

The company’s premise is that by incorporating the doorbell with cameras, you can create a “Ring of Security” around your home. It may not sound like much, but…