Version Number: V4.0.39b  
Release Date: 2026.03.19
Supported Printer Models: Bentsai 6105 series handheld inkjet printers

1.Resolve the issue of inaccurate ink-droplet counting.
2.This firmware version can only be upgraded from V2.0.23 or later. After the upgrade, only Bentsai BB21 and BB22 series cartridges will be recognized, while Bentsai 2580P and 2560 series cartridges will no longer be supported.