Billiard Cue Robertson RJ-1 Jump. The original Robertson cues have belonged to the absolute top class in terms of workmanship, quality and price for years. The newly developed jump cue has the ideal length of 104 cm and is especially perfect for very high jump bumps. The hard maple top is slightly tapered and equipped with a special jump fiber fabric ferrule and an original Robertson jump tip. With this Robertson "Jumper" even the hobby player can make successful jumps. You will be amazed!