Here is some advice from HockeyGiant.com on how to buy Goalie Chest & Arm Protectors

Function

Goalie chest and arm protectors are worn to do exactly what the name implies – protect the chest and arms of the goaltender. Chest and arm protectors are built with a nylon shell that contains numerous, segmented pieces of foam padding and plastic protective inserts which vary in size, shape and density. Protection should be the #1 priority for any goaltender, but a great C&A protector should be able to provide excellent protection without sacrificing mobility.

Construction Features

Foam Density & Segmentation

With protection, mobility and comfort in mind, manufacturers construct C/A protectors with several types of foams varying in density and shape. The foam padding and plastic inserts are strategically placed within the lining of the protector to optimize the overall fit and performance.

High quality C/A protectors, such as the Bauer Pro Senior Goalie Chest & Arm Protector, will often be constructed with more layers and padding segments than lower end C/A’s. In addition, high quality C/A’s are built with a broader variety of foam densities that provide an even greater level of protection, comfort, breathability and durability. In some cases, top of the line C/A’s like the Brians Zero G Chest & Arm Protector are constructed without any plastic inserts, and instead, contain extremely high density foam padding which is often lighter than the plastic which is typically used.

Beginner and mid level C&A protectors typically contain fewer foam density varieties than elite level C&A protectors. The Reebok 6K Chest & Arm Protector is a good example of a mid-level C/A which can be used for either inline hockey or moderately competitive ice hockey. These types of C/A’s sometimes contain fewer protective layers and padding segmentations, which means that the pads may not offer quite the same level of flexibility and mobility as elite level C/A’s.

You should always consider the level of competition at which you will be playing when you’re shopping for a goalie chest and arm protector. There’s no need for a rec. level ice hockey goalie to purchase a top of the line C&A protector. Use your best judgment when deciding how much protection you will actually need by taking into account the ability of the players who you will be playing against.

Adjustability & Coverage

Special Features

As is the case with any piece of protective gear, higher quality C/A’s offer more adjustment options and provide greater overall body coverage than lower level C/A’s. For example, the Bauer Elite Goalie Chest & Arm Protector comes with removable/adjustable lower abdominal pads. Certain C/A’s also have straps connecting the arm protectors to the shoulders which can be adjusted for additional length. These are convenient features that are worth considering because they provide goaltenders with an extremely customizable fit.

Bare Essentials

Every C&A protector is equipped with the bare essentials for adjustment in the key areas, such as the elbow straps and back/chest plate straps. The adjustment capabilities of these parts, although invariably essential to the construction of every C/A, can vary in terms of design quite a bit from model to model. Not every piece of gear is created equal. In fact, you might even find that you prefer the adjustment features of a lower end model from a particular brand over the adjustment features of a top model from another brand. Some use buckles, some use snaps and others use clips. Sometimes it just comes down to a matter of preference.

C&A Fit and Sizing

Goalies put themselves in harm’s way every game – arguably, more so than any other player on the ice. Proper-fitting equipment is essential to protecting yourself as a goaltender, so make sure that your C/A is not just comfortable, but also covers all parts of your torso that are vulnerable to flying pucks and swinging sticks.

Arms

The arm protectors should cover your arms from shoulder to wrist, with the end of the protective sleeves stopping just before the glove and blocker openings. There are usually several adjustment straps that can be used to tighten the padding around your wrist and elbow to secure the pads in place.

Chest

The chest protector should cover your shoulders, chest, abdomen and kidneys. Your hockey pants should meet the bottom edges of your chest protector with just a small amount of overlap. It’s very important, especially for ice hockey goaltenders, to make sure that your chest protector wraps around far enough to cover the sides of your rib cage. There are straps on the sides of the C/A that allow you to tighten the chest and back plates around your torso for a snug, secure fit. Most manufacturers will provide chest size ranges in inches for each chest protector size option that they offer. This is one of the key measurements that you’ll use when sizing yourself for a chest and arm protector.

Back

Back protection is important, and is incorporated in proportion to the degree of protection offered by the front side of the chest protector. High level C/A’s will, of course, have more back protection than entry level C/A’s. But, since goalies rarely have their backs to the puck, the need for back protection is far less critical than the need for front and side protection. Your back protector should cover your shoulder blades and the middle of your back, stopping short of the top edge of your pants.

C&A sizing can usually be determined with just two dimensions: chest size and height. When you’re ordering online it’s always important to refer to the sizing charts. In most cases, with just a few exceptions, C&A sizing is pretty consistent from model to model and brand to brand, so it’s a relatively easy piece of equipment to order without trying it on first. That being said, it’s always best to try on a few different models before making your final decision.