A scuba harness has two separate components: the backplate and the wing. Both are attached to a buoyancy compensationator which creates buoyancy below and above water. Backplate is modular and can be taken apart from the wing. These are great options for divers who aren't certain which type they should get. These pros and cons are listed below.
Stainless steel
You can have your stainless steel wings or back plate with or without a belt. The wings and backplate are made from 316 stainlesssteel. This material is highly resistant against saltwater. It is cut by a CNC router and polished manually to prevent any sharp edges from causing premature wear. They can also be used in conjunction with single-air-tank or dual air-tank systems. To make storage easier, you can take off the wings and backplate made of stainless steel.
Stainless steel backplates can be heavier than aluminum. Stainless Steel backplates are ideal for colder climates where they will decrease the weight that you'll be carrying during your dive. Unlike lead pieces, stainless steel backplates are easy to adjust to fit most dive tanks. A Halcyon Dealer may be able to give weighting advice so you can determine the best weight for your body. You won't need to replace this backplate as often because it will last longer.
Plastic
Although the plastic back plate/wing buoyancy is not ideal, it can still be useful for replacing weight on the weight belt. Jacket BCDs include pockets and weight integration. The wing and backplate do not have these ancillary functions. These components are available separately. We will be discussing the pros and cons for each. It is important to choose the right back plate for you.
Softpack harness
There are different types of harnesses for back plate and wings. Backplates, wing BCDs, and the most common are both available. These BCDs include all of the required components such as a backplate, wing, and harness. Users can also customize the harness using a range adjustable features. Softpack BCDs are perfect for technical divers as they are made from lightweight, flexible materials and are not attached with a rigid plate.
Steel backplate harnesses lack adaptability. The harness cannot be used with single tanks. It's only designed for use with double tanks that have permanent bands. The steel harness, while the most rigid, is also very cumbersome and difficult to use during travel. It is not suitable for single tanks and the steel backplate might be too heavy to use on the ground. You can attach adapters to make it compatible with single tanks. However, this is not recommended.