P.E Nation Backcheck Bike Short in Black. - size M (also in XS, S, L) P.E Nation Backcheck Bike Short in Black. - size M (also in XS, S, L) 78% recycled polyester 22% elastane. Made in China. Machine wash. Elastic logo webbing waistband. Stretch fit. Shorts measure approx 14.25 in length. PENR-WF40. 233S007_BLACK. P.E Nation is the pioneer of active, fashion, and street rolled into one brand. Each active piece is extremely high performance while also being breathable, smoothing, and lifting. Each collection is thoughtfully curated so that every piece can be worn back many different ways, giving you a plethora of options to style it your way. P.E Nation has infiltrated the athleisure market with wearable, fashion forward sports luxe pieces that can be mixed in with any modern wardrobe.