Suspension spring for movement model 101M manufactured from beginning of 1984 to present (please check the backplate of your movement for two-digit date listed above 451-050), 1161M and 1171M movements. Please check the back plate of your movement for "Hermle, two-digit year" and the number "451-050, or 1161, or 1171". This spring measures 1" long x 1/2" wide. Also fits 199/299M. FREE SHIPPING.