The scale uses a simple hydraulic principle to convert pressure into a reading in pounds on the gage. No delicate electronics, no batteries, and only one moving part. It is available with gages reading to 1000 lb, 2000 lb, or 5000 lb for 5th wheel trailers that typically carry a larger percentage of the overall weight on the gooseneck. Stop guessing and start towing safely. Reasonably priced for individual trailer owners. Great for travel clubs and trailer dealers too. The scale is machined from solid billet steel and aluminum. It has a 3.25" body diameter and is about 4.5" high without the included screw-on hitch extension. (6.75" with extension installed.) Actual weight is 4.4 lb. Gage diameter is 2.75".