The most unique aspect of the Spigen Slim Armor Pro is the hinge protection piece that covers the long hinge of the Z Fold 4 in the closed position. Samsung's phone hardware covers the hinge when in the fully open position, but when the phone is being carried around and the outside display is used then the hinge is susceptible to damage from a drop. This hinge is critical to the usability of the device itself so protecting it is important.
This year, Spigen also offers the Slim Armor Pro with S Pen holder for just $10 more. The S Pen slot is similar to the Thin Fit P design so this is the case to buy if you want it all.
The Spigen Slim Armor Pro case, available for $94.99, is a two piece case, like its other Z Fold 4 cases. The back cover has a large opening for the cameras and is cutout on the edge for the volume and fingerprint sensor areas with ample openings for the USB-C port and two microphones. The back is black with a soft touch matte finish and also has several yellow foam inserts to help with shock and provide protection to your phone.
The front is primarily a frame piece with the hinge protection part. The two pieces of the case fit tightly with double-sided tape acting to hold it in place as well. The matte finish soft touch frame part covers the edges with openings for the dual stereo speakers.
The hinge mechanism is designed with spings and an arrangement that has it sliding over the top of the back cover when the phone is fully opened. In the fully opened position when the hinge is hidden by the front and back of the phone, the hinge protector rests on the back panel. This actually helped me hold onto the phone a bit better with the grip of the hinge protection piece.
The Z Fold 4 rests mostly flat, with the exception of the camera array, when fully opened and set down on a surface. That's not the case with the phone wrapped in the Slim Armor Pro. There is now a large hump in the middle so the phone rocks on this arm.