Ultra's A35U Snap On Cap is designed to work with the new A44SG Screw-On Soft Tip. They fit the recessed groove on the bottom of the shoulder and fit the tip perfectly. These caps are made with an 85D Plastisol and they fit securely on the tip so you won't lose them through a hole. They won't come off when you are working the dent even under extreme pressure. A44SG Tip sold separately.