Bidirectional Ultrasonic Distance Measurement  Description:   Neilsen provides highest quality standards combined with reasonable price. Simply ideal choice for every professional, who is willing to use only quality products during work. Solid and efficient, that what you can expect from Neilsen tools and accessories!  Features: Measuring range:0.5-16M (Single Direction); 1-32M(Bi-direction);  Measuring precision :±1%; 60S auto turn off