The present invention generally relates to skin-mountable devices. A device in accordance with the invention comprises a first skin-mountable unit having a mounting surface comprising adhesive means for adhering the unit to the skin of a subject, and a second handling unit releasably attached to the skin-mountable unit. The handling unit comprises an interior space at least partially accommodating the skin-mountable unit and has an opening through which the skin-mountable member can be moved when detached from the handling unit, the handling unit having a portion surrounding the opening. The device further comprises a seal member releasably attached to the circumferential portion, thereby providing a closed space for the skin-mountable unit. In this way a device is provided allowing for easy handling as a user can use the handling unit to grip and handle the combined device during operation thereof, just as the second unit can be designed and optimized for ease of use during manipulation of the skin-mountable unit.