Whistler McMorris Back Shield for cycling and winter sports, including snowboarding and skiing designed to protect against the risk of impact.The McMorris back shield is supposed to sit in close contact with the body.If the wrong size is chosen, its protective ability will be reduced.When choosing the right size of back shield, always be guided by the distance between your waist and shoulders, as there is no constant relationship between your body height and body structure.The length between the waist and shoulders is the longest possible vertical length at the back and is measured from the waist to the highest point on the shoulders.In this case, the waist is measured from the top of the hip bone. Size S M L XL Height 185 Body 39-41 41-43 43-45 45-47 For the back shield to work properly, it must cover the entire protected area - always remember the zipper after use.The back of the rear shield should snug, but not tightly.Always check the closure system and location before use.The back shield does not guarantee protection against twisting or extreme movements, but is designed to absorb back impacts if the user is involved in a collision.The windshield is crash tested according to EN1621-2-2014+CN-B/P/09.014 rev02 and is classified as Type FB (=FULLBACK) Level 1 (Level 1)In addition, the Whistler McMorris rear shield was subjected to a pre-crash test at -20 degrees to prove its performance in low temperatures.The back shield is not recommended for use in colder conditions.