You can pop a loose back protector into an existing motorcycle jacket, or opt for the HELD Exosafe Back 2. In that case, the loose D3O back protector comes ready-fitted in a lightweight harness with adjustable waistband and shoulder straps.
Motorcycle jackets now come in all shapes, sizes and styles. Impact protection does too. It's no longer a given that both have to match perfectly. For anyone wanting a standalone back protector regardless of the outer layer, this is an excellent solution. The combinations are as broad as you make them.
The HELD Exosafe Back 2 consists of a D3O back protector and an adjustable harness. D3O material stays flexible while riding and only hardens on impact. This is a Level 2 version. The harness features mesh panels and a 3D air-mesh lining on the back, so you don't overheat right away. The waist strap adjusts via Velcro. The shoulder straps are elastic and lengthen or shorten via a buckle.
Attention: this is a standalone protector worn underneath your jacket; it is not an integrated solution. That means an extra clothing layer and thus a bit more bulk.
For anyone seeking extra protection without buying a new motorcycle jacket, this is a solid compromise. For those wanting to take it up another notch, look towards the HELD Exosafe Vest 2.