Belgium Flag 3x5 Brand NEW 3 x 5 BELGIAN Outdoor Banner by Flags Unlimited. $4.99. Made To United Nations Specs. Durable Polyester Material. Our international flags are accurately reproduced to exact specifications. The flag has 2 grommets on the left edge. These polyester flags not recommended for prolonged outdoor use. For outdoor use, we recommend our nylon flags.. Save 75%!