Amazon.com : The Firewood Gauge (17”) - The Original Patented Magnetic Firewood Measuring Tool – Strong Durable Flexible Fiberglass with a Whopping 88 Pound Pulling Force Magnet attaches to Any Chainsaw Bar :
Amazon.com: Riomhorry Firewood Measuring Tool, Adjustable Firewood Cutting Tool Freely Adjust between 16'' and 26'', Firewood Gauge Attaches to Chainsaw Bar to Measure Firewood Length : Patio, Lawn & Garden