The glass bead sterilizer operates by exposing instruments to high temperatures using heated glass beads. However, its effective sterilization is limited to small and lightweight instruments because larger or bulkier tools cannot be adequately exposed to the heat uniformly. This limits the mass and size of instruments that can be sterilized, making it unsuitable for heavier surgical equipment. Additionally, the rapid heating nature requires instruments to be small enough to allow thorough heat penetration within a short time frame.

Reference: Surgical Instruments: A Pocket Guide, Maryann P. Hogan, Third Edition.