Corona FlexDIAL with ComfortGEL Grips Bypass Pruner (BP 4214): Product Review

Ease of Use


Cutting Performance


A novel idea that needs to go back to the drawing board.

Overall Score


Available on Amazon

Buy It

When I first saw the Corona FlexDIAL with ComfortGEL Grips Bypass Pruner I thought of the famous Star Trek line, “Beam me up Scotty”. It was like the pruner said, “Dial me up Jack”. Turning the dial makes an adjustable grip possible.

What Does the Adjustable FlexDIAL Do?

The purpose of the FlexDIAL is to provide an adjustable grip for different size hands. The 1 position on the dial is for the smaller hands. For larger (XL) hands, there is a dial position of 8.

As the dial position approaches 1 the blade cutting diameter decreases, and as the dial position moves toward 8 the cutting diameter increases. When you rotate the FlexDIAL’s dial you can see the blades opening and closing as the handles do the same.


FlexDIAL sets the pruner into one of 8 positions depending upon hand size

Setting the Dial

While I noticed that the flex dial could only be set while holding the pruner in my right hand, the pruner itself is ambidextrous once the dial is set.

Technically, the dial operation requires the effort of only one hand – you can rotate the dial with your thumb and index finger while holding the pruner handles. However, I found it easier to move the dial using both hands – grasping the handles in one hand and the dial in the other makes it easier to adjust.

I found adjusting the dial to be a trial and error process. To make the dial easier to rotate, I had to squeeze the handles together. Then, as I rotated the dial from 1 towards 8 I would have to periodically let go of the handles to see the actual handle distance.

Comfortable ComfortGEL® Handles Act as a Bumper

Corona has developed a handle technology called ComfortGEL®. It’s very comfortable to hold and also acts as a bumper. Conventional bypass pruners incorporate a rubber-like bumper between the handles to reduce shock as the handles hit together at the completion of a pruning cut. Corona takes a different approach by using the ComfortGEL® in the handle itself as the bumper.

The ComfortGEL® is constructed from a soft, spongy-like material that reminds me of a silicon coating. It has an excellent grip with both gloved and ungloved hands, and also worked well when my hands were wet or sweaty.


The ComfortGEL® handles are very comfortable and eliminate the need for separate bumpers

Cutting Capacity Varies With FlexDIAL Setting

Corona claims that the FlexDIAL bypass pruner has a ¾ inch cutting capacity and I found that estimate to be spot on – I was able to cut through ¾ inch wood with the dial in the 8 position. As I adjusted the dial to 1, the cutting capacity went to ¼ inch. Setting 4 produced a 3/8 inch cut.

Adjusting the pruner from position 8 to position 1 also makes the cutting opening between the blades significantly smaller. This really limits the cutting diameter for those with smaller hands. It’s nice to have the adjustability, but at the expense of cutting diameter, hmmm.

On a positive note, the larger and smaller cuts were clean and precise (prior to the blade bending, see below). Even pruning small non-woody stems produced the same clean result.

Blade Lock Was A Problem

The blade lock is a thumb button that can be locked with a simple thumb movement. However, I found that it had two problems.

First, the blade lock was very hard to operate – sliding the thumb button back and forth was difficult and took a lot of effort.

Second, the button would not hold the pruner closed. No matter how hard I pressed the button into the lock position, it would not stay locked. Looking closer at the mechanism it was clear that the locking pin just kept slipping out of the locking slot.


The blade lock would not engage and the pruner did not stay closed

Cutting Blade Bent and Developed a Large Burr

The pruner worked fine out of the package (except for the locking mechanism). But after I made several cuts in ¾ inch wood (which it could easily handle), the cutting blade bent. When the bent blade hit the counter blade (non sharp blade) it caused a significant burr and a small piece of the cutting blade partly sheared off, creating a much larger burr.

Given that the blades are made from high carbon steel, I really didn’t expect the cutting blade to bend like that.  I didn’t even cut any wood on a bias, which will often cause blade spread (and possible bending), although even in those instances the blades usually pop back into place.


The blade developed a significant burr. The cutting blade bent and I had trouble closing the pruner.

Other Features

The cutting blade is coated with a non-stick material. This aids in its cutting ability and helps prevent sap build-up.

The chassis is full steel construction. From the tips of the pruner to the end of the handles is a steel frame.

The FlexDIAL pruner uses a volute spring for tensioning the blades. This type of spring is a sealed
helical steel coil that keeps debris out of the spring and doesn’t tend to get caught on things as you’re pruning.

No Replacement Blades

Due to its construction (full steel construction), there are no replacement blades. The good news is that the blades can be sharpened. I recommend the Corona Sharpening Tool (AC 8300). It is available from the Corona website.


The pruner comes with a limited lifetime warranty against defects in materials and workmanship.


The Corona FlexDIAL with ComfortGEL® grips bypass pruner (BP4214) has a unique adjustment system (the FlexDIAL) that adjusts handle width (and cutting capacity) for those with different size hands. It initially made clean cuts through material up to ¾ inches while in the highest width setting (it will only cut ¼ inch stems while in the ‘small hands’ position). However, the cutting blade quickly bent and the thumb lock didn’t stay locked, making it unusable. It’s unclear whether this is a quality control issue or a design flaw but at this time I cannot recommend this pruner.

Where to Buy

The pruner is available from Corona on their website  for $35.53 + $9.48 shipping. It is also available from Amazon (Prime) for $29.95.

And now over to you – Have you used an adjustable pruner before? How did it work? Let us know in the comments below!

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