Size: 16 inches per letter Material: aluminum foil Packing: color cardboard + Opp bag Function: birthday party decoration Content: Happy birthday letters + bubble blowing straw + 10M rope product description Color: black//white Material: Aluminum Foil Letters: 13 Pieces Color: Multicolor Optional Size: 16 inches/piece Packaging: Happy Birthday Letters x13 pieces (16 inches) 1 piece of 10m ribbon (3.9 inches) Plastic straws x 1 piece (5.7 inches) Tips: The design of the letter "B" is special, before it is inflated, it looks like the letter "C"), and the letter "B" after inflating. The machine detects all aluminum foil balloons. If air leakage occurs during inflation, please press the inflation hole or use tape to help seal the balloon automatically.