High Quality Construction| All Sper Scientific immersion thermometers are made with safe red liquid to SAMA specifications for ranges and accuracy. In addition, our thermometers have a number of extra quality features built in:• Red Liquid Expansion Chambers• Reinforced Bulbs to prevent breakage • Horizontally Printed Scales are easier to read in use • Ring Tops for submersion • Non Roll Caps • Scales Printed Into The Glass rather than on the surface so they never wear off.