; and (B) the member is selected by the Secretary of the Air Force, based upon the needs of the Space Force and the grade and military skills of that member. (3) Limitation on time in mobilization category A member of the Space Force in a space force active status may not remain designated an Individual Ready Guardian in such mobilization category after the end of the 24-month period beginning on the date of the separation of the member from active service. (4) Designation of grades and military skills or specialties The Secretary of the Air Force shall designate the grades and military skills or specialties of members to be eligible for placement in such mobilization category. (5) Benefits A member in such mobilization category shall be eligible for benefits (other than pay and training) on the same basis as are available to members of the Individual Ready Reserve who are in the special mobilization category under section 10144(b) of this title, as determined by the Secretary of Defense. 20103. Members not on sustained duty: agreements concerning conditions of service (a) Agreements The Secretary of the Air Force may enter into a written agreement with a member of the Space Force not on sustained duty— (1) requiring the member to serve on active duty for a definite period of time; (2) specifying the conditions of the member’s service on active duty; and (3) for a member serving in a space force inactive status, specifying the conditions for the member’s continued service as well as order to active duty with and without the consent of the member. (b) Conditions of service An agreement under subsection (a) shall specify the conditions of service. The Secretary of the Air Force shall prescribe regulations establishing— (1) what conditions of service may be specified in the agreement; (2) the obligations of the parties