The Thermo Fischer Eclipse Orbitrap improves upon the earlier model to create a mass spectrometer with even stable, high mass accuracy resolution at even faster scan rates (40Hz). The newer version uses ion-funnel optics to better focus the ions through 2 separate traps, high pressure for better collision and low pressure for quicker ion detection. The Orbitrap Eclipse is also equipped with a High Collision Dissociation cell and an Electron Transfer Dissociation cell. These two different collision cells provide an alternate means of fragmentation from the standard front-end ion trap. HCD is often utilized to experimentally detect and analyze low mass ions such as the reporter ions used in TMT/ITRAQ experiments in high-resolution or to discover other peptide modifications. ETD fragmentation uses the fluoranthene anion to react chemically to the peptide backbone to create fragments with intact modification and side chains.