ISO D Die Spring, Heavy Duty, Color Red, Chrome Silicone Alloy Steel, Finish Powder Coat, Overall Length 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 705.8 lb./in., Meets/Exceeds ISO10243