Sterling Hollow Block


★★★★★ (5 out of 5)

Climbing cord is probably the least sexy of all climbing gear, right up there with slings and webbing. If you are a seasoned climber, you know the utility of cord far exceeds its low cost. For new climbers, cord is likely lower on the list of needed gear and you might not totally understand all the various scenarios where it can be used.

When I first started climbing, I would see people backing up rappels with a third-hand and scratch my head. It seemed easy enough to always keep a firm grip on the brake and ask your climbing partner for a fireman’s belay in case things went south. It wasn’t until a climbing rescue course that I learned all the benefits that a simple piece of cord can afford.

The Sterling Hollow Block is a must have climbing accessory if you are going to be rappelling, multipitch climbing, or want to become more hands on with different usages of cord.


$25 | Where to Buy


It’s hard not to give a simple piece of functional safety climbing gear a high rating. Cord is one of the most simple and versatile pieces of gear you could have on your climbing harness. The Sterling Hollow Block is just that and a bit more. Tie friction hitches with more bite and heat resistance compared to nylon climbing cord.

The Good

The Bite

Unlike nylon cord, the Hollow Block is made with Aramid fibers and a hollow core, hence the name, allowing the fibers to bite on a rope 7mm or larger using a Prusik or Klemheist. It holds very well when knots are tied correctly. We’ve used it plenty of times on a 9.8 Sterling Velocity rope in rappel situations.

Abrasion and Heat Resistant

The Aramid fiber construction protects against abrasion and heat better than typical nylon. This isn’t a huge concern in most cases, but it does help you swallow the price of the Hollow Block compared to regular nylon cord knowing it will likely last longer. It also slides easily away from the load when needed, meaning it isn’t a nuisance when used as a backup.

Sewn Ends

This can go either way when comparing to the versatility of cord. Having sewn ends means the Hollow Block has limited functionality, but that means it does what it was made to do very well. You don’t have to worry about tying your cord and the little extra bulk that comes with it. The sewn ends are protected with a rubber sheath of sorts for likely increased durability.


The 13.5” loop is a good size for tying your friction hitch without leaving a lot of added material to get in the way of things. A larger size is available if you feel like it’s needed


There a many uses for Hollow Block with the most obvious being backing up your rappel with a third hand. It can also be used to tie a friction hitch for a number of other use cases including ascending a rope or setting up a mechanical advantage.

The Not So Good


Compared to simple nylon cord, the Sterling Hollow Block is pricey. That said, it offers up a better solution for friction hitches, so you get what you pay for.

One Trick Pony

At the risk of contradicting ourselves, the Hollow Block is a one trick pony in that it should only be used for friction hitches. It shouldn’t be used in a load bearing manner.

Final Verdict

If you are spending time climbing outside, having a Sterling Hollow Block is worth the price tag. It provides a more secure way to back up a rappel or tie friction hitches and almost always comes in handy at the crag. Even though it costs more than average nylon cord, it’s still a cheap, small, lightweight and functional piece of gear to hang from your harness, so why not?

How To Tie Friction Hitches

There are a few simple friction hitches that every climber should know. Check out the video below to learn how to tie an auto-block, Prusik, and Klemheist. Each is fairly easy to remember and comes in handy for different uses cases. More on that below.

Using Friction Hitches

A simple friction hitch is critical to a variety of climbing scenarios. The most common are for backing up a rappel or belay, ascending a rope, or setting up a mechanical advantage. Check out the videos below to learn more about each.

Backing up a Rappel

Any time you are rappelling off a climb, it’s prudent to have a back up to your break hand just in case. It comes in especially handy on single pitch climbs if you are having to clean draws on a bolt line that isn’t directly beneath you. On multipitch climbs, it adds redundancy in a rappel situation where you might not have a partner at the bottom being able to provide a fireman’s belay.

Ascending a Rope

An unplanned ascension of a rope is never the most fun in the world. It’s a good skill to have for scenarios like falling into space on a steep route where you can’t get back on the rock.

Mechanical Advantage

Having to move a partner up a climb while belaying from above isn’t all that uncommon. Setting up a mechanical advantage at the belay station provides extra power to pull a climber up. This is another common scenario where a friction hitch and Hollow Block come in handy.


$25 | Where to Buy