Principle Two: Flexibility of Use
The design accommodates a wide range of individual preferences and abilities.
Great Grips can be used on doorknobs, water faucet handles, valve/tank handles, and large pill bottle caps. Great Grips are easily trimmed with scissors to custom-fit any of these applications, and can be stretched to over 300% their original size.

Principle Three: Simple and Intuitive Use
Use of the design is easy to understand, regardless of the user's experience, knowledge, language skills or current concentration levels.
Great Grips assume the shape of any knob they are placed on, making their function simple and clear for users to discern. Great Grips install in less than a minute without tools.

Principle Four: Perceptible Information
The design communicates necessary information effectively to the user, regardless of ambient conditions or the user's sensory abilities.
Great Grips are designed to be inconspicuous, but users will immediately feel the cushioned softness at first touch, while the nine ribs and mini-lever facilitate turning the knob with less effort, pain, and discomfort. The mini-lever can be placed anywhere on the circumference of the knob to suit user preference (example: position the mini-lever for dominant hand of frequent user).

The Great Grips Glow-in-the-Dark feature helps sighted-users find doors and exits in power outages and darkness. For non-sighted users, the Great Grip may serve as a tactile indication for an escape route with placement on exit doorways.

Principle Five: Tolerance for Errors
The design minimizes hazards and the adverse consequences of accidental or unintended actions.
Great Grips are manufactured with latex-free Dynaflex and require no maintenance. The Dynaflex also has an ultraviolet (UV) inhibitor to reduce sunlight deterioration. The luminova glow material will glow for 6+ hours and only needs exposure to light for effect. If Great Grips get dirty, simply wash them in a dishwasher.

Principle Six: Low Physical Effort
The design can be used efficiently and comfortably with a minimum of fatigue.
The Great Grips reduce the effort necessary to twist and turn doorknobs by increasing the gripping surface and increasing the co-efficent of friction. Great Grips create an affordable mechanism for existing doorknob hardware to be opened with a closed fist (Standards for Accessibility and Design, aka ADA Accessibility Guidelines 4.13.9).

Principle Seven: Size and Space for Approach and Use
Appropriate size and space is provided for approach, reach, manipulation, and use regardless of user's body size, posture or mobility.
Great Grips only add 1/8" to the existing circumference of a doorknob, and the 1/2" mini-lever can be positioned on the knob in any orientation to accommodate the the preferences of the user.