Semi-Automatic-Label-Dispensers Tach-It Semi-Automatic Label Dispensers are available in 6 different models for labels up to 8 inches wide. Unlike other manufacturers in the industry that use micro-switches to sense the label, most of our Tach-It label dispensers use non-contact, state-of-the-art photo-sensors and optical readers. The advantages of this system are many, first micro-switches are mechanical and break needed replacement, also they must be physically moved using tools each time a label size changes or as the roll decreases and the curl of the label changes. Our non-contact sensors are more reliable, and the only adjustment for label size is a simple turn of a knob located on the front of the dispenser which adjusts the length of the label to be fed. We do make one exception and use a specially designed micro-switch for our ultra-economical Tach-It SH400 Label Dispenser.