Frequently Asked Questions

The inventor of the Rock Block, John Horter, answers these questions in this 3 minute video.

Why is the Rock Block better than metal screens or plexiglass shields?

The Rock Block installs easily, swings out of the way, is higher quality, doesn't obstruct the view, and is often the same price as a new window. Unlike metal screens or plexiglass, the Rock Block stays on the machine and doesn't need to be moved.

How does the Rock Block work?

Simple installation, permanent solution.

Rock Block kits are unique to different models of machines. Our kits bolt onto your machine easily, using existing holes when applicable. Our curtains are specially designed to be durable yet flexible to give you optimal cutting and long life. The kits do not hinder your view and still allow you to access your cutter bar. Most kits take less than an hour to install on your machine.

Does the Rock Block affect how my machine will cut after it’s installed?

The short

We farm as well and have done extensive testing of our product. Our curtain is specially designed to be flexible and very durable. In our testing, we have found that cutting quality is not affected as long as you have the kit installed properly and the correct amount of drag is achieved. We recommend the curtain to be just barely dragging on the ground. For very tall crops, we suggest setting down your skid shoes and tipping your machine back to give you a larger opening.

Will your kit fit my machine?

We carry kits for about 16 of the most common-style machines and are adding more to the list all the time. We also have a universal kit that is available to fit most 9’ mowers. If your machine is not available, please contact us as we are often able to adapt our existing to most machines. As interest grows in new models we add them to our product line.

Why should I purchase a Rock Block?

Even if you don’t have rocks or have never broken a window or been hit by debris, odds are sometimes you will! Your safety is our concern, and our kits are often times less expensive than windows and definitely reduces your risk of injury! Be proactive and not reactive. I can’t count how many times I’ve taken the phone call “I was meaning to buy one of your kits, but I didn’t before I broke a window!” Quality and customer service are of utmost importance to us!

Why is the Rock Block superior to the factory curtain?

The Rock Block curtain is made of a specially formulated rubber that is stronger than factory equipment. It is flexible and durable, offering peace of mind to the operator and a clean cut when installed properly.

Is the Rock Block easy to install?

Most Rock Block kits can be installed in under 90 minutes, using factory holes and provided hardware and instructions. Video instructions are also available.

Does the Rock Block come with a warranty?

We offer a 1-year warranty on workmanship issues and welcome feedback to improve our product.

How will the Rock Block affect cutting performance?

Our specially formulated rubber material is flexible and durable, providing the same performance as the original curtain. Trimming may be necessary, guided by our instructions.

Where to buy the Rock Block?

Available at and from implement dealers, or contact us directly, we’ll be happy to help.

Is cutter bar access hindered by the Rock Block?

The larger Rock Block swings out of the way and our smaller kits flip up for easy access to the cutter bar.

What if my machine isn't listed in your fitment guide?

We offer universal kits that can be adapted to fit, or contact us for guidance.

Can I replace the factory curtain with the Rock Block?

We do not recommend replacing the factory curtain with the Rock Block as it may impair cut quality.