Help identify tube power for Redsail M900

I just purchased a Redsail M900 Laser engrver. This machine was still in the crate and unused but it did not have the laser tube installed or in the crate. It was purchased as abandoned freight.

I would like to purchase the laser tube for this machine but I understand that they came in various watts (60W, 80W, 100W) but I do not see the wattage marked on the machine or power supply anywhere and do not want to purchase the wrong one. I sent a message to the manufacturer with the serial number asking about the wattage but have not heard back from them.

Most of the online pictures I saw of the M900 60W had the left side of the machine where the tube goes flush. This one has an extension box on it. The tube holder brackets are right at 3" in Diameter and most of the 60W tubes I saw are closer to 2".

I have attached some pictures. Any help would be appreciated.