The Bailey Monofilament is an instrument used for testing peripheral neuropathy. It does this by applying a specific force to a point on the skin to assess the sensitivity of the skin at that point. The force applied is determined by the buckling load of the monofilament, which is transferred to the point of contact. The load applied to a monofilament may be increased until it buckles, after which a constant force is transferred to the point of contact. The actual force applied is determined by the length and the diameter of the monofilament and by the mechanical properties of the material. The length and diameter are carefully controlled in manufacturing. The monofilament material has been carefully selected for its consistent mechanical properties over a range of environmental conditions.