Attachment systems for electronic devices

A band system for securing a watch to a user, the band system comprising:

• a sizing band comprising multiple first engagement features, the sizing band having a first sizing band width, the sizing band width extending across one of the multiple first engagement features and to edges of the sizing band;
• and
• a retaining band comprising:
• a first portion;
• a second portion;
• a third portion;
• a concealment aperture extending through a thickness of the retaining band at the second portion;
• a second engagement feature at the first portion and configured to engage one of the first engagement features;
• side walls extending from opposing sides of the concealment aperture;
• and
• a recessed guide bed at the third portion and extending from the concealment aperture, between the side walls, and along a length of the retaining band, wherein an end of the recessed guide bed, opposite the concealment aperture, forms a curved shape that matches a curved shape of an end of the sizing band, wherein a first width across the first portion is equal to a third width across the third portion, wherein a second width across the second portion is greater than the first width and the third width, the first width being equal to the sizing band width.

A band system for securing a watch to a user, the band system comprising:

• a sizing band comprising:
• a first securement end configured to attach to a housing of the watch;
• an insert end;
• and
• multiple first engagement features along a middle portion of the sizing band between the first securement end and the insert end, the middle portion having a sizing band width;
• and
• a retaining band comprising:
• a first portion having a first width equal to the sizing band width;
• a second portion having a second width greater than the sizing band width;
• a third portion having a third width equal to the sizing band width;
• a second securement end configured to attach to the housing of the watch;
• a concealment aperture extending from a first surface of the retaining band to a second surface of the retaining band at the second portion and opposite the first surface;
• a second engagement feature on the first surface of the retaining band and at the first portion;
• and
• a recessed guide bed formed in the second surface of the retaining band and at the third portion;
• wherein the sizing band is configured to extend along the first surface of the retaining band with the second engagement feature engaging one of the first engagement features, through the concealment aperture, and along the second surface of the retaining band with the insert end only partially within a depth of the recessed guide bed.