Universal PAG Oil for all R134a systems. Double-end capped for stability. Convenient 8oz Spot-gun cartridge allows oil to be injected cleanly, accurately and quickly into a pressurized system. Graduated cartridge allows accurate top ups of systems . From the recognized leader in UV leak detection Uview designs and manufactures and delivers the most innovative and functional products to the automotive repair industry. This convenient 8oz cartridge utilizes the award-winning spot-gun injection system. Also has the ability to inject a precise amount of oil into a pressurized system via the low side service port. This helps to eliminates contaminates from entering the system. It's simple to use, with its one step process! Today's vehicles require precise amounts of oil and specific viscosities, OEM's have deemed it essential, shouldn't you?