he blue Tenura non-slip jar opener is designed to help those with a poor grip to open jars.This domed shaped design means it\'s suitable for most jar sizes. Its ridged, soft outside provides a strong and firm grip when being used with either your fingers and thumb or the palm of your hand. It offers optimal amounts of comfort. This opener will come in useful for people with arthritis or any condition that weakens hand grip. This device can be operated with one hand, with a Tenura non-slip mat underneath the base of the bottle to stop slipping and sliding.