TSC (Thermally Stable Composite) offers thermal expansion characteristics similar to those of aluminum. Parts made with TSC deform less, making possible lens construction of extremely high precision. As compared to polycarbonate containing 20% glass, a commonly used material, TSC offers approximately 70% higher elasticity. As compared to polycarbonate containing 30% glass, it offers 25% higher elasticity. (Comparison is between SIGMA-produced components.) Since thermal shrinkage is low, it has high affinity to metal parts which contributes to high quality product manufacturing.