Grainger has contacted the product supplier and have been advised by them of the following:
This detector is Certified Pre-Owned. This means the supplier no longer makes this item new. What you would be purchasing is a refurbished unit. It uses calibration station 31KZ40 which is also Certified Pre-Owned. You would also need regulator 9RA92 and calibration gas 8G506. That is for automatic calibration. If you prefer manual, you would need the same cal gas (8G506), but regulator 8YKN2 as well as tubing 9CUG7.
I'm unsure what you mean by type of plug to charge the battery. The monitor comes with a cradle charger that the monitor snaps into for charging. The plug that goes into the wall is a standard wall plug for 120 volts. If you need further information please reach out to us at 1-800-GRAINGER (472-4643).
Thank you for using Grainger Ask and Answer