MRS Climbing Devices

Buying guide

What an MRS device does

In moving rope climbing, your line runs from your saddle, up over an anchor and back down to your friction system. The climber advances by pulling slack through the system. For decades that meant a friction hitch and a hitch-tending pulley. Mechanical MRS devices do the same job with metal parts that grip the rope through a cam, chain or bend path.

The appeal is consistency. A hitch can grab differently when cord is new, worn, wet or hot. A mechanical device behaves the same from the first climb of the morning to the last, as long as it is used on a compatible rope and kept clean.

Mechanical devices also reduce the heat that builds up on long descents, which helps protect your climbing line and gives you smoother control when you are lowering yourself out of a big tree.

Building an MRS climbing kit

Start with the device and check its approved rope diameters and rope types against your climb line. Then add connectors the manufacturer approves, a small pulley or swivel if the device is designed for one, and a friction saver or ring set for the anchor. Rings from our rings section are a common choice.

Many climbers keep a friction hitch setup as a backup and for rescue scenarios. Knowing both systems makes you a more flexible climber.

If you plan to move between moving and stationary rope, look for a device that is approved for both. Converting between modes usually means adding or rearranging components, and the steps must follow the manual exactly.

Write down what you build and keep it the same. A consistent setup is easier to inspect and easier for a crew partner to check during a buddy check or a rescue.

Choosing a device

Think about how you climb most. Long limb walks and big spreading trees reward a device with very fine descent control. Fast production climbing on smaller trees rewards something quick to install and easy to tend. Weight, how easily the device releases with gloves on, and how well it handles a dirty rope all matter on a real job.

Ask other climbers on your crew what they run, and try a device before you buy if you can. For stationary rope options, see our SRS climbing devices page.

Price matters too. A good MRS device is a real investment, so it pays to choose one that fits your rope, your trees and your style rather than chasing the newest design.

Training and inspection

Mechanical devices change how your system behaves under load, and misrigging can be serious. Learn a new device from a qualified trainer, rig it on the ground, and test it before every climb. Keep it clean of sap and grit, check moving parts for wear, and retire it if anything is cracked, bent or worn past the maker's limits.

Anything you hang your life on must meet the applicable standard, be used per the manufacturer's instructions and ANSI Z133, and be inspected before every climb by a trained user.

Keep the device's manual with your kit or saved on your phone, and recheck it whenever you change rope or connectors.