Seiko D138-5050 Watch Guide The Seiko D138-5050 is a watch model based on the D138 movement.Parts ListES2W18GN00crystalEC0060B0Aothers - button gasketOther models with the same movementD138-4000D138-4009D138-4010D138-4020D138-5000D138-5010D138-5030D138-5040