usun

hi i have an USUN GBD40-OL i check to buy fitting hose i saw some kit like https://nuvair.com/o2-clean-hose-kit-with-analog-gauge.html https://www.divegearexpress.com/deluxe-fitting-and-hose-kit more then 75% of the price of the booster.... is there any other alternative?

A while back I had a computer crash that corrupted a lot of the manuals that I had. Googling doesn't find it, so I figured I'd ask here, does anyone have a PDF of the User or repair manual for the GBT-15/40-OL?