Alpinestars Bio Armor Back Protector Features Direct replacement for Alpinestars RC Back Protector which has been discontinued Optimized for insertion into the latest Alpinestars technical jackets. Slimline profile. Conformable impact absorbing compound mold easily to the body. Perforated to improve the breathability. CE certified level 1 to latest prEN1621-22010. Please see below chart for protector measurements Size Measurements Small 14.5 Height 9.75 Widest Point 6.5 Narrowest Point Medium 16.25 Height 9.5 Widest Point 6.75 Narrowest Point Large 18.5 Height 10 Widest Point 6.75 Narrowest Point (function() var cycle true ('table.sizechart tbody tr').each(function(row) classname (cycle !cycle) 'light' 'dark' row.addClassName(classname) ) )()