Mountainsmith Circuit 3.0 Internal Frame Backpack - Lightweight Hiking Backpack for Outdoor Adventures, Camping & Travel - Durable 50L Backpack with Adjustable Straps & Multiple Pockets

If you are heading out into the backcountry for a long trip, the new and improved Circuit 3.0 will handle a week or even a months worth of gear. This pack has plenty of organization, a detachable lid that converts into a lumbar pack and all of the comfort you could ever ask for. Heading out into the backcountry for a long trip? Check out Mountainsmith's Circuit 3.0 internal frame backpack, which handles a week's or even a month's worth of gear. The pack is loaded from a storage perspective, with a volume of 5,370 cubic inches and such details as a zippered vertical front compartment with elastic rigging, a vertical front pocket, zippered side pockets with pass-through sleeves, and a host of internal organizer pockets for items like Swiss Army knives or bathroom extras. Mountainsmith knows that proper hydration is a must while on the trail, which is why the pack also comes with a pair of 32-ounce water bottle pockets and a hydration pocket that holds a hydration bladder and tube system (sold separately). As with the best terrain packs, the Circuit 3.0 stands up to inclement weather, offering both a collared storm shield with a draw-cord closure and a water-resistant clear map case. And for those times when you need a little extra assistance on the trail, you can turn to the single ice-axe loop and the trekking pole mounts. Other features include a separate sleeping bag compartment with an internal divider, sleeping pad compression straps with quick-release hardware, a fleece-lined eyewear pocket, a key clip, and a safety whistle. Comfort is always a concern on the trail, and the Circuit 3.0 excels in this area as well. The pack is equipped with the Mountainsmith's Load Dispersion Technology Suspension system, which consists of independently adjustable shoulder straps with dual-density foam, an elastic sternum strap with a bite valve catch, a molded foam back panel, a pivoting waist belt with dual-density foam and an HDPE sheet, and four load adjusters that help you balance the weight comfortably on your hips. The detachable lid, meanwhile, also serves as a lumbar pack, so you can steal away for a short hike without hauling along all your gear. The Circuit 3.0's construction details include 420d Velocity nylon body fabric, 840d Ballistic nylon reinforcements, twin 1-inch concave aluminum stays, YKK zippers, and bar tack and Hypalon reinforcements. Measuring 18.5 by 33.5 by 17 inches (W x H x D) and weighing 5 pounds, 4 ounces when empty, the pack offers a fit range of 18 to 22 inches and is backed by a lifetime warranty.Amazon.com Backpack Guide Finding the Right Backpack For extended trips into the backcountry, there's no getting around the fact that you'll have to carry life-sustaining supplies on your back. Here are some things to keep in mind when shopping for a backpack:Internal vs. External Up until late 1970's, external frame packs--which consist of an exposed, lightweight metal frame attached to a fabric pack-bag--were the only thing going. In recent years, though, packs that place the support structure of the pack inside the pack, known as internal frame packs, have boomed in popularity. The good news about internal frame packs is that they hold the weight of your load close to your body, making it easier to maintain your balance on uneven terrain. Meanwhile, internals provide stiffness and support, but they are not completely rigid, which makes them more flexible when you're doing active sports. With the added flexibility comes a high degree of compressibility, meaning you can use the pack's compression straps to cinch down your load and keep items from shifting and throwing you off balance. Internals also sport slimmer shapes that allow for more arm movement in all directions--another big plus for off-trail bushwhackers, skiers and climbers. Last but not least, internal frame packs offer a greater range of adjustability in the shoulder harness and hip-belt than external frame packs. There are some negatives for internals. First, once packed, it can be difficult to grab needed items out of them quickly. And because internal frame packs consolidate the load into a single, body-hugging unit, proper packing is very important. To distribute the weight properly, you should pack your heaviest items close to your back and in the middle portion of the pack-bag. Plan on getting a sweaty back with an internal, too, given the fact that they are pressed right against you. Finally, internal frame packs are priced higher than external models. External frame packs are very good at focusing the weight of a load directly to the right place: your load-loving hips. While internals, when properly packed, do this effectively, too, you can always rest assured that an external will distribute the load evenly, no matter how unevenly packed it may be. Externals also offer easy access to your gear via multiple, easily-accessible compartments. Plus, because externals don't situate the load directly against your back, you'll enjoy far more air flow. Finally, if you're on a budget, or you're buying for a growing child, externals are more affordable. If you plan on hiking on easy to moderate trails and you don't need a lot of body movement, you'll probably be fine with an external. But because externals are so rigid and inflexible, challenging trails or any kind of off-trail pursuit can become painful and frustrating. Also know that your balance is far more compromised with an external frame pack during activities like stream crossings and hops through talus fields.Packs for Shorter Trips In addition to backpacks designed for overnight trips, rucksacks are great for day-trips, warm-weather one-nighters, single-day ski trips, or fast alpine assaults. Some rucksacks blur the line between backpack and rucksack with integrated internal supports and sophisticated hip belts and shoulder harnesses. Choose a pack in this category based on your intended use. Short day hikers don't need an internal frame, while climbers and skiers with heavier loads likely do.Sizes and Capacities Packs in the 3,000 cubic inches and lower category are good for day hikes or overnighters in warm weather with minimal gear. Packs in the 3,000 to 4,000 cubic inch range are good for one- or two-night trips in colder weather. If you're going to be out for up to three days, look for a pack in the sub-4,000 cubic inch range. Choose a pack with 5,000-6,000 cubic inches for week-long outings. And finally, for trips lasting a week or more, you'll need something in the 6,000-plus cubic inch category. Keep in mind, though, that bigger packs weigh more, and since every ounce counts, you'll want to choose a pack that offers just enough space for your outings and no more.