I recently purchased the Measuring Gauge and was very impressed with the quality of materials used. However, the user must be aware that when measuring girth that the gauge is overlapping itself which adds the thickness of the device to the girth measurement. Similarly, the measurement is made on the outside of the gauge, not the inside. This adds the thickness of the gauge to the girth measurement a second time. The end result is that approximately 1/8 inch or 3 mm is added to the diameter x 3.14, which adds 3/8 inch or 9 mm to every measurement made. I checked this with a tailor's tape, measuring three rigid cardboard tubes of varying size and the Bathmate gauge consistently measured 3/8 inch or 9 mm greater than the thin tailor's tape. To obtain an accurate measurement of girth, simply subtract 3/8 inch or 9 mm from your result. Users should especially keep this in mind when measuring to determine girth for the best fit of condom as using the non-adjusted measurement would result in a severe risk of slippage.
This issue aside, I cannot stress enough how well made the device is nor how easy it is to use when compared with fiddling with a tailor's tape or string. Used with care and precision it is indispensable.