A hearing aid kit includes a standard fit, completely-in-canal (CIC) hearing aid and a hearing aid tool set. The CIC hearing aid is for extended use and includes a core module inserted into a sleeve. The core module and the sleeve each include various features providing for a minimum overall size, ease of insertion, removal, and cleaning, and enhanced sound transmission. The tool set is configured to be stored and carried in a single piece and provides for adjustment and cleaning of the CIC hearing aid. Open ear fits and occlusive ear fits are possible using different sleeves.