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What is the Perform Fiber Bag?
The Perform is an innovative bag which uses the legendary Ajungilak synthetic insulation to provide warmth down to sub-zero temperatures. It moves away from the standard design with a zip at the side and puts it on the top, slap bang in the centre.
What is it made of?
Outer fabric: A tough nylon outer fabric encapsulates the legendary Ajungilak insulation and features a durable water repellent coating to deal with condensation and general moisture. Mammut have made this fabric feel as soft as your duvet at home, yet far, far tougher for rugged outdoor use.
Insulation: The legendary Ajungilak insulation is used throughout the bag. Ajungilak have been creating insulation since 1855, so they're pretty good at what they do. This insulation is made entirely from synthetic materials, meaning if it gets wet it'll still provide warmth; useful if you accidentally spill a drink over yourself (not speaking from experience, honest).
Inner: The lining fabric has been designed, much like the outer, to feel like a duvet you'd have at home, creating a 'homely' feeling and therefore allowing you to sleep better.
What are the features?
Probably the most unique feature is the centre zip. Rather than your standard side zip which is generally difficult to find and undo in the dark, Mammut's centre zip never snags and can easily be undone no matter what position you're in. The centre zip also massively improves ventilation and allows you to either unzip from the bottom to ventilate your legs, or from the top for greater heat dissipation. A magnet at the top of the zip seals the bag up to your neck and is super easy to undo, just give it a pull. There's also a drawcord to compress the hood and insulation collar for greater warmth.
Another unique feature is the inclusion of a sleep mask and earplugs — this relates to the 'perform' part in the title; the bag is designed to give you the best nights sleep possible so you can perform the following day. A specific fabric is used in the hood which is quieter than your average fabric, further reducing noise if you're not using the earplugs. Even if you're not using the mask or plugs, they can be neatly stashed away in the internal pocket, keeping them within arms reach. This is also a great place to pop your phone to prevent it losing battery in cold conditions.
How does it fit?
It features what Mammut call a 'restorative' fit, meaning there's more than enough room to comfortably move about during the night, yet not so much that it takes hours to warm up. A cleverly shaped footbox allows your feet to sit in their natural position during the night, preventing it compressing the insulation.
- Restorative fit
- Central two-way zip
- Soft material in hood
- Magnetic closure
- Hood drawcord
- Internal pocket
- Included sleepmask and earplugs
- Includes stuffsack
- Anatomical footbox
- Insulated zip cover
- Snag-resistant zip
How warm a sleeping bag do you really need? We’ve tried to help you by grouping our sleeping bags by their recognised comfort ratings. These are the ratings supplied by the brands that indicate the temperature at which you will remain comfortable whilst sleeping on an insulated sleep mat. After all, comfort is what you want when it’s cold and wet outside, and you’re all tucked up in your nice warm sleeping bag.
We always recommend that you choose your bag according to the coldest conditions you will experience; you can always unzip a bag if it is too warm, but trying to sleep when you’re too cold is just miserable. Bear in mind that we are all individuals, so we all feel the cold differently and that our own resistance will fluctuate depending on a whole load of factors, including how much we have eaten, whether we have consumed alcohol, whether we need a wee or what kind of mood we are in!
Sleeping bags do not generate heat; they only trap the heat we produce, so it is vital that you get into your bag when you are giving off warmth, don’t go to bed when you are cold, have a hot meal or a hot drink or do some brisk exercise to get you nicely warmed up.
Traditionally sleeping bag manufacturers provided their own temperature ratings based on their experience, the product's intended end-use and the perceived environment. However, each brand tested their bags in different ways, and it was hard to find a fair comparison between models. So, in 2005 a European standard for sleeping bag temperature ratings, EN 13537, was introduced to give consumers a comparable guide to sleeping bag performance across a range of brands and models. The ratings have four different temperature ratings to give you an indication of the bag's performance.
Comfort Rating: This is the temperature at which an average female should experience a comfortable night’s sleep. On average, women sleep colder than men, so this rating is some degrees above the "comfort lower limit" for a man.
Comfort Limit Rating: This is the lowest temperature at which an average male should experience a comfortable night’s sleep whilst laid down in a curled up position.
Extreme: This is a survival rating where the user is likely to suffer health damage such as Hypothermia. It should be treated with the utmost caution and not be relied on for general use.
However, the EN 13537 European Standard does not apply to down-filled sleeping bags with a fill weight of more than 800g; for those bags, you will have to rely on the manufacturer's experience and technical expertise, which is often more accurate!
Most reputable brands still use their own rating system alongside EN 13537, for instance, Mountain Equipment's “Good Night’s Sleep” and Rab’s “Sleep Limit”. These ratings are often the most accurate guide to the overall performance of a sleeping bag being used by an average outdoor enthusiast because they are based on years of expedition heritage, field trials, technological experience, and constant feedback.
But please bear in mind that all ratings are only a guide and, as mentioned earlier, there are a huge range of factors that can affect your comfort; if you are just not sure, it is always wise to go for a warmer model.
The biggest difference you can make to your overall comfort is to use an efficiently insulated sleeping mat. Once you get inside your sleeping bag, you instantly compress all the filling beneath you, greatly reducing its efficiency. Therefore using a quality sleep mat will ensure you are properly insulated from the cold ground, and you will be a lot more comfortable... Basically, there is no point in buying a top-quality sleeping bag if you are just going to lie down on the floor.