ISO D Die Spring, Medium Duty, Color Blue, Chrome Silicone Alloy Steel, Finish Powder Coat, Overall Length 1-3/4 In., Outside Dia. 1-1/4 In., End Type Closed & Ground, For Hole Size 1-1/4 In., For Rod Size 5/8 In., Spring Rate 778.8 lb./in., Meets/Exceeds ISO10243