Extension Spring Ultra Precision 302 Stainless Steel Plain End Type Full Twist Loops Overall Length 2 1/2 In Outside Dia 0.500 In Wire Dia 0.055 In Load 11.38 Lbs Deflection @ Load 2.32 In Initial Tension 1.04 Lbs Spring Rate 4.43 Lbs/In Meets/Exceeds ASTM A313 and AMS 5688 Package 3