Under Armour Threadborne Training Baseball Cap Mens. Under Armour Threadborne Training Baseball Cap MensTrain in style in the Under Armour Threadborne Training Baseball Cap - a six panel design, with the back four being flexible, in a classic fit, with breathability perforations and a curved peak. Subtle Under Armour branding completes the look.> Men's training baseball cap> 6 panel design - back 4 being flexible> Classic fit> Breathability perforations> Curved peak> Under Armour branding> 100% Polyester