For demanding applications where highly flexible, impact-resistant bonds are required, Master Bond Inc. has developed Polymer System EP37-3FLF. This optically clear, two-component epoxy exhibits good resistance to cryogenic temperatures and severe thermal cycling. Its low exo-therm also makes it a good potting, encapsulating and casting system, especially where wider cross-section thicknesses are specified. Its combination of properties allows it to cure without stressing delicate electronic components. Serviceable over the range of 4 K to 250 °F, the epoxy cures at room temperature in two to three days, or faster at elevated temperatures. It offers a convenient, noncritical 1:1 mix ratio by weight or volume, and a low mixed viscosity of 1400 to 1500 cycles per second. It bonds well to a variety of substrates.