Loop Mainspring-5/16" X 0.15" X 42"
Frankenmuth Clock Company™
SKU: MS-273
MS-STshoulder
Loop End Mainspring
11/16" X 0.014" X 120"
17.5mm X .36mm X 3048mm X 50mm barrel
Often used on Seth Thomas T& S Shoulder movements
High Quality. Made in Germany