If problem on installation, plz contact us. As experience, 99% cases could be fixed. Compatible with Seiko 63Mas 40.5mm models SBDC051, SBDC053, SBDC055, SBDC059 SBDC077, SBDC085, SBDC101, SBDC103, SBDC105, SBDC107 SBDC139, SBDC141, SBDC153, SBDC163, SBDC165, SPB051, SPB053, SPB071 SPB143, SPB145, SPB147, SPB149, SPB213, SPB239, SPB253, SPB297 Strapcode Guarantee: Upon receiving our goods, If you are having problems with the fitting with our products or other issues, please feel free to contact us. As experience, 99% cases could be fixed.
Tips for not fit: use smaller spring bar. Plz contact our team to request for a set of different sized spring bars to rectify the matter.
Tips for clasp locking loosely: it's friendly design for easily open, please visit our V-Clasp version if need totally closed version.
Tips for avoiding scratches: put some tape or oil on lug when installing.

Item number: SS201820B121

Full compatible model list:
Compatible with Seiko 63Mas 40.5mm models SPB143, SPB145, SPB147, SPB149, SBDC101, SBDC103, SBDC105, SBDC107

Introduction: This Super-O Boyer watch band with curved solid end pieces is compatible with Seiko 63Mas Prospex SPB143, SPB145, SPB147, SPB149 with Dia. 40.5mm models. Super-O Boyer watch band is a new breakthrough of our O Boyer Collection. This well-built replacement bracelet was assembled with screw-in.
Brand: MiLTAT
Style Name: Super-O Boyer
Lug width (mm): 20
Buckle size (mm): 18
Thickness (mm): 3.2
Spring bar hole dia. (mm): 2.00
Material: 316L Stainless Steel
Color / Finish: Brushed
Max. length (mm): approx. 185
Min. length (mm): approx. 110
Net Weight (gram): approx. 97
Lug end style: Curved End
Adjustment type: 6 Screw fixed links & 6 micro holes on clasp