Cosmos &reg; Pack of 3 Light Brown Dual Heads Aluminum Pencil Lengthener Extender Holder Aluminum dual head pencil lengthener When your pencil becomes too short to hold, just insert it into this handy tool and carry on using it It becomes a writing instrument by making shorter pencils feel more balanced as it allows for a better grip. Double head, one head diameter is approx 7mm, the other head is approx 13mm 12.8cm (5 inch) long