The Zebra DelGuard introduces a new lead breakage prevention mechanism to the market by absorbing some of the writing pressure within the internals of the pencil. As with all new products on the market that introduce new features, it boils down to does it work as intended. In the case of the DelGuard, it does.
When I first saw the DelGuard I assumed by the similar looks that Zebra was going for a Kuru Toga type mechanism, but that is not the case. Instead, they built in cushioning inside barrel in the form of a spring and lead pipe that adjusts as you write.
My concern with the DelGuard is that I would feel the mechanism working as I was writing, but that wasn't the case at all. I prefer firm mechanical pencils and it felt as if I was writing with any standard pencil. That's good design. Do your job while not interfering with the expected experience.
I'm a medium to heavy pressure writer and never once broke the lead writing normally. When I increased my writing pressure gradually the lead stayed intact as well. Of course you could push it to the breaking point with extreme pressure or extending the lead too far, but the DelGuard handles everything else admirably.
If you enjoy mechanical pencils and lead breakage is holding you back, then give the Zebra DelGuard a try. At $7.50 it's not exactly cheap but if it can eliminate frustration it may be worth it.
(JetPens provided this product at no charge to The Pen Addict for review purposes.)