This makes an Equalized, Small Angle, Redundant, No Extension, Strong, & Timely anchor. Practice at home before you use this tool in the mountains. It is an anchor to be made when other options do not exist.
To take it a step further, one of the non-locking carabiners can be omitted by girth hitching the dyneema sling to the wire of the stopper/cam/piton. Warning: when dyneema is attached directly against the wire of the nut, it significantly reduces the fabrics durability, and you are effectively leaving trash on the mountain. BUT, and this is a big but, if that is what the situation requires, then that is what you need to do to be safe. If you are girth hitching a cam or piton, that is better for the sling durability.
For example. You are climbing a big alpine route. You are moving slower than you anticipated, and the afternoon thunderstorm comes in faster than anticipated. Bailing off the route becomes your best option, even though you have 1500 feet (450m) of unknown terrain to rappel through. You only have 18 pieces total on your rack. That will allow for nine, 2-piece, anchors. So you now need to be very conservative with the use of your rack...this anchor is key in that scenario, or anything like it.
I'll buy the gear you used to make your anchors safe
Leaving gear sucks, especially when you are leaving multiple pieces at a time to create redundant anchors. Dying sucks more, esp for your partner and your mother. Trying to decide if that one nut, or that sun faded single piece of tat is "good enough" to rappel off is a lame place to be. Thinking that every additional piece left is at least $12 plus $7 for the carabiner. It adds up fast, and justifies worse and worse bail anchors. With that in mind, I want to help remove the financial aspect of your decision. So here's the deal.
If you are in a dire situation in the mountains, and need to create an anchor(s) to bail off, I will replace your second and third piece(s) of gear, per anchor, for free. To redeem this offer, tell me the situation, with photos of the anchor and your partner's facial expression saying, "thanks for making the decision to make safe anchors an easy one for us Mark!" And I'll replace those pieces of gear for free. You buy the first piece, and I buy the second piece, per anchor. I'll buy the third piece too, if that is what you determine is needed to make that anchor safe. This is per anchor. So if you blow through your entire rack getting off a route safely, thats fine, I'll support up to 9 anchors per epic. Fine print: This offer is good until Oct. 5 2017, and only applies to climbers and skiers under 30 years old. If you are 30+, you are more financially secure and hopefully it's easier for you to make self-preservation decisions. If it is clear to me that you are placing crappy, dangerous, pieces, I will not replace your gear until you hire an IFMGA guide to teach you better protection placement techniques. I will give you recommendations of a guide located near you if needed. Lastly, if you die from a rappel anchor failing, I will not replace your gear.
If you want to learn more about anchors in the ski mountaineering world, I suggest joining me in Peru for a chance to ski from 17,000+ foot tall glaciated mountains, May 2017. Check out the expedition details here.
Rather go climbing? I am guiding an Alpamayo climb. It is an ice and snow climb that takes you to 19511' in the heart of Peru's Cordillera Blanca!
Again, let me know if you have question.
Be safe. Live to climb another day.
IFMGA Mountain Guide