The Spine Ergo is a lightweight back protector, with shoulder straps and a height adjustable flexible waistband system for the best individual fit. The back plates are made of Polypropylene and have an inner shock absorbing core made of multi impact EPP. Thanks to the Air Induction System that transports moisture and lets fresh air flow in, it has great ventilation. Spine Ergo is the alternative if you prefer to use a light weight hard shell protection with multi-impact shock absorbing properties.