The shuttle type grease tube system does not require the spring loaded loading handle used with old style grease guns. I can't say what a mess I make when the lever pops out of the loading groove and grease goes everywhere as I am trying to screw the barrel on to the grease gun head.
The shuttle screws into the head of the grease gun, no spring loaded rod to leak!
In this link, scroll down to shuttle grease tube video and watch
The LockNLube Premium Pistol Grip Grease Gun delivers up to 8,000 PSI. A cast aluminum head combines extreme durability and lightweight construction. A large ergonomic handle means you have more grip on the grease gun, and an integrated handle clip makes storage clean and easy. Variable Stroke...
locknlube.com
View attachment 362701
You don't have to buy the shuttle grease system from Lock N Lube, many places to buy their brands.
Also, empty shuttle tubes can be purchased so you can load them with the grease you want to use.