Extension Spring, Ultra Precision, 302 Stainless Steel, Plain, End Type Full Twist Loops, Overall Length 4 In, Outside Dia 0.500 In, Wire Dia 0.063 In, Load 16.34 Lbs, Deflection @ Load 3.07 In, Initial Tension 1.48 Lbs, Spring Rate 4.78 Lbs/In, Meets/Exceeds ASTM A313 and AMS 5688, Package 3