The 2024 advanced Grubber-Bar was designed to protect the rear of molding while placed in the clamp. It equalizes the clamping pressure, self-correcting the 90-degree angle to match the miter (auto adjust up to 3 degrees). It also improves the clamp grip of the frame while allowing the elastic supple rubber to play its magic and optimize the surface contact at the joint. In addition, that low profile rubber spacer allows better access to the rear of the frame, so framers can have hands-on when joining and see about adjusting/aligning the corner if/when needed. you need two grubber bars for one corner, if using 4 clamps you'll need 8 grubber bars.
There is much more to say about this advantage. However, we researched it for a while, tested it, and know how NanoTech and science can be employed here. In short, we found it practical, optional, and all the excellent staff. Although resistant, the rubber strip (mounted on the aluminum bar) can be replaced easily (grubber roll available onsite). Looking back, I am curious to know how we did without it.
This product is designed for V5-basic, V5-Pro, and V5-Reverse. w