There are several reasons but the primary 3 reasons include:

• Take the pain out of spraying aerosols.(tm) Daily aerosol users (whether DIY or Professional) may experience pain to parts of the actuating finger(s) which can lead to numbness, tingling, weakness, or muscle damage in the hand and fingers; Similar to carpal tunnel syndrome, a condition in which there is long term pressure on the users median nerve. 
• Ease of use. The vGrip handle and trigger work perfectly even with your protective work gloves are still on your hand(s) as they were meant to be, and not pulled off and stuffed in your back pocket.
• Aerosol Handling The handle allows users to keep fingers away from caustic chemicals, solvent and oil based paints, dangerous fixatives and more.  The vGrip also limits the potential for severe frostbite depending upon propellant composition.

There are many reasons but the primary 2 reasons include:

• Comfortable Trigger. vGrip’s ergonomic trigger leverages 4 finger use maximes spray consistency and even distributes pull pressures across your hand. 
• Engineered in the USA, vGrip fits on all standard aerosols and actuates more button types and designs. Aerosol handles that are cheaply designed in far away Countries lack integrity and American know-how.  Consumers will find more expensive products on the market that fail, where Aerosol Handle users need to ball up painters tape for example, in order to bridge the gap between competitors trigger mechanism of their handle and the aerosol button. 

vGrip is Made in the USA, manufactured using recycled plastics

The vGrip easily snaps on most standard aerosols heads, right where the silver valve crimps onto the top of the aerosol can. The user simply insures that the spray nozzle and oriface in position so when the vGrip trigger is pulled, the spray delivery will not be obstructed.  Once the trigger is pulled the aerosol button will actuate. 

Preval Sprayers, Insecticides, Lubricants Sprays, Brake Cleaners, Industrial Chemicals, Plastidip Sprays, Spray Paints, Primer Sprays, Protective Coatings, Fixitive Sprays, Carb and Choke Cleaners, Hobby and Craft Sprays, Glass Cleaners, Wax and polish sprays, Whitewall Cleaners, 2k Aerosols, Upholstery Cleaners, Tire Cleaners, Degreasers, Dusting Aids, Cutting Oils, Air Freshners, Marking Paints, Varnish, Shellac, Stain, Anti-seize Lubricants, Electronic Cleaners, Glitter Sprays, Battery Terminal Coatings, Dry Moly Lube, Dry Graphite Sprays, Foamers, and so much more the list could go on and on.

Yes.  The vGrip is designed to be remounted on multiple aerosols, and built to be used in all environments.