Upgrade Maintenance Charm through four ranks and it tops out at Tool Specialist Lv4. The first rank costs 1,500z to craft, every rank after that is an upgrade. Some of the materials only come from Congalala, Gravios, Jin Dahaad and one more monster.
Rank by rank
Maintenance Charm IRarity 4
Tool Specialist Lv1: Shortens recharge time by 10%.
Craftable · 1,500zMaintenance Charm IIRarity 6
Tool Specialist Lv2: Shortens recharge time by 20%.
Upgrade from previous rank · 6,000zMaintenance Charm IIIRarity 7
Tool Specialist Lv3: Shortens recharge time by 30%.
Upgrade from previous rank · 9,000zMaintenance Charm IVRarity 8
Tool Specialist Lv4: Shortens recharge time by 40%.
Upgrade from previous rank · 16,000z