MODEL 2261 MODEL 2284 MODEL 2292 MODEL 4130 MODEL 4200 MODEL 2281 MODEL 4303 MODEL 4313 MODEL 4503 MODEL 4513 MODEL 4304 MODEL 4504 MODEL 2265 MODEL 4135   3" HEAD DIAMETER - Dual Fahrenheit and Celsius scales Designed to meet the needs of the amateur or professional The Solar® Weston exclusive MIRROBAND® dial eliminates parallax error All stainless steel construction Unique stainless steel clip adjusts the thermometer for tray or tank use...or for hanging on any projection in the darkroom Outer Fahrenheit scale is black and the inner Celsius scale is red Dual scale has clearly defined numerals and divisions indexed at 68°F and 20°C 3" head diameter Stem length: 6" Spiked Accuracy: ± 0.25% at 68°F and within ± 1% over the remainder of the range Range: 25° to 125°F External adjustment for calibration    Model 4315 - 6" Stem Length   Range(°)   Model / Catalog No.   25 to 125 °F   4135-O6000NF Note: Model 4135 can be recalibrated by means of an external adjustment by firmly holding the head and immersing the stem at least two inches in an agitated known controlled temperature bath and turning the hex nut at the base of the thermometer head until the pointer indicates the correct temperature.