SummaryA collar to fit on an Estes Ascender body tube. It protects the end of the tube from damage when it hits the ground on re-entry. It has a 5.1cm diameter. I had to sand the inside to get it to fit perfectly. I sanded the outside to get the smooth aerodynamic look.InstructionsPrint it. Sand the inside to get the right fit. Glue it to the end of the rocket about 20mm down.