Safety Testing

Over the years there are three questions related to safety that we are consistently asked:

Is the Seatbelt Adjuster certified?

Has the Seatbelt Adjuster been safety tested?

Can the Seatbelt Adjuster be used with a Booster Seat?

Certification  We have not found any governing body that regulates 'Seatbelt Tension Devices', however, National Highway Traffic Safety Administration (NHTSA) had this to say about such devices: 
  "these devices have been used extensively for the last 16 years... no evidence exist to show these devices are being misused to create exess belt slack nor is there proof that using th edevices causes real-world problems" 
  Click here to view the NHTSA report on Seatbelt Tension Devices 
Safety Testing  in an independent test by Miller Engineering in 1995, they used dummies of a 6yr old child (47lbs) and a Adult Female (105 lbs) they reported the the following findings: 
  "...the adjuster did not interfere with the seatbelt restraint system. The adjuster fractured early in the test as was intended which permitted the seatbelt to release from the adjuster and operate as it normally would for the particular configuration." 
Even though the testing was done without a Booster Seat, we strongly recommend use of a Booster Seat. 
The purpose of a booster seat is to provide a proper fit with a seatbelt designed for an adult. By boosting the child, the safety restraint can better protect them in the event of a crash. Proper fit includes a lap belt that fits flat across the child's upper thighs and a shoulder belt that sits in the middle of the shoulder firmly.

Lap belts that ride over the abdomen can increase the likelihood of a soft-tissue injury versus the more stable and bony structure of the pelvis. An ill-fitting shoulder belt is less safe and can ride up on the neck of a child or off the shoulder, causing discomfort which leads children to readjust the belt, often resulting in an ineffective restraint.

This item is to provide added driving comfort and is not a safety device. There is no guarantee that the adjuster will eliminate the possibility of injury in serious car crashes. Do not compromise the effectiveness of your seat belt; check your vehicle manual for length allowance on shoulder restraints and the importance of properly fitting the lap belt snugly across the hip and pelvic area.

Click here to view findings or Click here for Full 8 Page Report

Can the adjuster be used on a Booster Seat?

Especially on the backless models...

Yes, and also other plastic clips....see the following reports.

The Insurance Institute for Highway Safety (IIHS) 
have stated:

"...They may require a plastic clip to properly position the shoulder belt."

Click here for the 3 page Article Re: Use plastic clip if needed on Booster and Height, Age and Weight. Scroll down to 'Yellow' highlight.

Click here for the full 8 page IIHS report on Booster Seat Brand Ratings and Rankings.

See what NHTSA has to say:

For more information on Booster Seats click here
For information on Booster Seat Laws in your State click here

Safety Tests and Ratings

What does the NHTSA ( National Highway Traffic Safety Administration) say about seatbelt adjuster devices?


Answer: "no evidence exists to show these devices are being misused to create belt slack nor is there proof that using the devices cause real-world problems"

Findings: NHTSA recognizes the potential benefits of a device which can increase seat belt use by providing increased comfort to users through additional belt adjustments.

Test Results From Miller Engineering: I am pleased to report that in all the tests with the Master Design Seatbelt Adjuster, the adjuster did not interfere with the seatbelt restraint system.

For the complete engineering report including child and adult age and weight test info click here.

Safety Information and Statistics Regarding Seat Belt Use.

Did you know that when a driver buckles up, children are buckled up 87 percent of the time. However, when a driver is unbuckled, children are restrained only 24 percent of the time.

If you are aware of a friend or loved one that refuses to wear their belt due to discomfort give them a Seatbelt Adjuster ™. You might save their life now that they have no excuse not to wear their seat belt.

There are 33% fewer fatalities when passengers wear both lap and shoulder belts. Keep your family safe by using seat belts. Seat belts are only effective if they are used properly.

Note: The Seatbelt Adjuster ™ is not a safety device. It has been designed to add comfort for drivers and passengers, motivating them to use their seatbelts properly. This increases their overall driving safety.

For more detailed and indepth copies of the testing which was completed on our product by a highly regarded engineering firm see below.

If you do not have the FREE Acrobat Reader installed - click here to download.

Safety Information Listed Below:

Buckle Up America Information  Buckle-Up America
Safety phamplet from NHTSA (3397 KB)

Safety Facts

National Safety Council - Passenger Restraint
Safety Articles  Safety Charts
Charts and Statistics (388 KB)

The Miller Testing Report
The full testing report (1352 KB)

Executive Summary
Summary from engineering firm (348 KB) 
Safety Article 1  Adv. Specialty & Promotional Ideas.
Using the Seatbelt Adjuster (265 KB)

Masterlink in the News
News article about our product (229 KB)

Drinking and Driving 
Safety phamplet from NHTSA (6185 KB)

How to Buy a Safe Car
10 features that can save your life (257 KB)

NHTSA Calendar of Events

Safety Statistics


National Highway Traffic Safety Administration
  Seat belts save lives. In 1999, motor vehicle occupant restraints saved the lives of an estimated 11,197 people over age four. If all passenger vehicle occupants over age 4 used proper restraints, an additional 9,553 lives could have been saved in 1999.  
  In 1999, nearly 19,000 unrestrained drivers and passengers died in traffic crashes—more than 3,000 of them were children.
  In 1999, more than 60 percent of the children killed in traffic crashes were completely unrestrained.  
  Seat belts reduce the risk of death for front seat occupants in passenger cars by 45 percent and the risk of moderate to critical injury by 50 percent.  
  Strong enforcement of adult seat belt laws saves not only adults, but children. The American Academy of Pediatrics found that a restrained driver was three times more likely to restrain a child. NHTSA observational research shows that when a driver buckles up, children are buckled up 87 percent of the time. However, when a driver is unbuckled, children are restrained only 24 percent of the time.

  Officers do not want to give out tickets but they do want to save lives. You can avoid a ticket by buckling up on every trip, every time you get in the car, no matter how close your destination is. 
  Motor vehicle crashes are the leading cause of death for Hispanics through age 24, and the second leading cause of death for Hispanics aged 25-44.  
  Motor vehicle crashes are the leading cause of death for African American children through the age of 14. Crashes are the second leading cause of death for African Americans aged 15-24.

Safety Organization Links

Please take a few minutes to view some of these Safety Oriented Websites. If you would like to be listed please email thewebmaster, thank you.
  Buckle Up America - Every Trip - Every Time. 
  The National Highway Traffic Safety Administration (NHTSA) 
  Page of Sealtbelt Use Information. 
  Transport Canada Public Safety 
  The Insurance Corporation of B.C.