Not All Motorcycle Helmets Are The Same
Full Face, Modular, Three Quarter, Half and Dual Sport/Off Road helmets are the five common types of motorcycle helmets. Only motorcycle helmets that are DOT certified will be discussed here in this article. A popular style of motorcycle helmet that does include some DOT models is known as a beanie.
The DOT (Department Of Transportation) puts helmets through a series of four tests that they must pass to be DOT certified. The helmets must pass an impact test, penetration test, a strap retention test and a peripheral vision test. In states where helmets are mandatory by law, they require any helmet worn by the rider or passenger be DOT certified.
There are many helmets that can be found for sale online or sold by vendors at motorcycle shows and events that are not DOT certified. They are usually less expensive than DOT models, understandably so. The standards they are manufactured to are lower, and many are made using cheaper materials. Most of the non DOT helmets would not pass the impact and penetration tests. Some riders like these because they are small, lightweight and usually inexpensive.
We do not recommend using non DOT helmets when riding.
The Highest Level Of Protection
The highest level of protection for on-road motorcycling would be the Full Face and Full Face Modular helmets. For off-road riding the Dual Sport/Off Road helmets are the highest.
These helmets provide the most coverage of a riders head protecting the top, back, sides and face. The Modular style 
should be worn with the hinged chin bar front pulled down and locked when riding for the most protection.
Some riders prefer the Modular as it is less claustrophobic and offers the ability to pull up the front of the helmet when stopped providing more rider visibility and to converse with other riders.
Full Face and Modular style helmets will provide the best protection not only in the unfortunate occurrence of an accident, they will protect the riders face from wind, rain and the occasional flying insect. Most riders have experienced the needle like sensation on their face from even light rain when traveling at moderate to highway speeds. Even a windshield on your motorcycle cannot block out all the rain, bugs or objects you may encounter when riding.
Three Quarter and Half Helmets
If you prefer your motorcycle helmet to be less restrictive and more “open air”, then you likely would be looking for Three Quarter or Half style helmets. They are less claustrophobic and are lighter that the full style helmets. These styles understandably offer less protection from accidents/falls and the weather so 
it is critical that what ever helmet you use is DOT certified. Some Three Quarter helmets
offer the option of a fixed or operable visor to provide more eye protection.
Where to Find Your Helmet
We highly recommend the following brands of helmets. They are high quality and have some of the highest safety ratings. All are reputable companies that stand behind their products and have great customer service. They are in no particular order:
https://shoei-helmets.com https://www.nolanhelmets.com https://www.bellhelmets.com https://www.araiamericas.com https://www.scorpionusa.com https://www.schuberth.com https://www.flyracing.com https://www.hjchelmets.us https://rideicon.com/ https://beaniehelmets.com/