17mm Mainspring £ 5.50 Spring Size Height 17 Strength 25 Length 25 Height 17 Strength 30 Length 30 Height 17 Strength 35 Length 35 Height 17 Strength 40 Length 40 Height 17 Strength 45 Length 45 Add to basket View basket Category Mainsprings Product Codes: MS172525 & MS173030 & MS173535 & MS174040 & MS174545