TM-1151 Ultrasonic Tape Measure

My friend is an Architect so I decided to give her the TM-1151 Ultrasonic Tape Measure (UTM) as a Christmas Gift. I field tested the gift for her. And I must say that I have mixed feelings about the device. The UTM is that size of about 2 scientific calculators placed back to back. It uses a 9-volt battery. And it works using the principle of sound waves, where you send out a wave and wait for it to echo back. In order for the tape measure to actually work, you have to be facing a literal perpendicular wall so that ultrasonic sound can bounce back. Even the slightest angle can result in the signal getting lost, resulting in a reading that will display ERROR. The laser pointer is great for checking if you are pointing in the right direction, but it is only useful at night. If there is a lot of foliage, or obstructions between the wall and you, then expect an ERROR signal once again. So while the device claims an accuracy of between .5% to 1% deviations, getting an actual reading will be a challenge. If you are on a geological survey team, with nothing but nature on the field, then this gadget is not for you since how many natural rock formations resemble an actual perpendicular wall? So this device will only probably work great in urban areas. The device advertises a maximum range of 60 feet. But I was only able to measure a maximum distance of about 10 meters. So again, think twice before you even make this purchase. I'll try to field test the device first before actually paying for it.