First Strike USP 100 .50 Cal Blue/White 600.60 DKK First Strike's Ultra Sphere Projectiles (or USP) in .50 cal shape. Completely round paintballs. Made with a plastic shell and powder filling. BUY Helt runda .50 kaliber paintballs! Skal av plast, med pulverfyllning Share Article Number: 2292 Information Reviews Bag with 100 .50 cal USP rounds from First Strike. Completely round and filled with powder.