Attachment system for an electronic device

A watch band assembly for a wearable electronic device having a channel and a recess, the watch band assembly comprising:

• a band strap configured to attach the wearable electronic device to a user;
• a removable module coupled to the band strap and configured to be removably coupled to the wearable electronic device, the removable module comprising a body defining a top surface and an opening extending into the top surface;
• and
• a locking mechanism configured to lock the removable module to the wearable electronic device when inserted into the channel of the wearable electronic device, the locking mechanism comprising:
• a catch member having a chamfered edge extending either to the top surface of the body or into the opening;
• and
• a spring mechanism facilitating movement of the locking mechanism between:
• a first position, while the locking mechanism is outside the channel, with the catch member being proud with respect to the top surface of the removable module;
• a second position, while the locking mechanism is partially within the channel, with the catch member substantially flush with the top surface of the removable module, wherein the chamfered edge actuates the locking mechanism from the first position to the second position when the chamfered edge contacts the channel of the wearable electronic device;
• and
• a third position, while the locking mechanism is inside the channel, with the catch member protruding out of the opening into the recess.

A watch band assembly for a wearable electronic device, the watch band assembly comprising:

• a removable module configured to be removably coupled to the wearable electronic device, the removable module comprising a body defining a surface and an opening extending into the surface;
• a catch member moveable within the opening, the catch member comprising:
• a substantially planar top surface;
• and
• a chamfered edge extending from the substantially planar top surface at least to the surface of the body, the chamfered edge being configured to actuate the catch member as the removable module is inserted into a channel and the chamfered edge contacts the channel;
• and
• a spring mechanism configured to bias the catch member to be proud of the surface of the removable module.