Drive DeVilbissSerena

How we test comfort

This star rating compares comfort of legs, buttocks and back in upright and recline positions. Those with the highest comfort ratings get the most stars.

How we test feeling secure

Feeling secure looks at how safe you feel as the chair moves you from perching or standing position to sitting - and back again. Those chairs that maximise your feeling of security get the highest number of stars.

How we test ease of use

This looks at how easy it is to use the hand controls and work the various functions of the chair. It also compares instructions and how easy they are to understand. Chairs with the most stars are the easiest to use.

How we test speed of operation

The time taken in minutes and seconds to move through various chair positions eg sitting to standing in minutes and seconds. The faster the chair, the higher the score.

How we test back-up battery performance

This looks at how reliable the back-up battery is. The more stars a chair has, the more likely it is to work effectively. One with five stars exceeds our expectations when it comes to reliability.