The Wildebees size 4 & 5 rugby balls are high performance match rugby balls for schools and clubs. This rugby ball weighs 450 gram (World Rugby max spec=460 gram). Excellent kicking ball due to its rounder shape. This result in a higher and quicker energy displacement. (In the size 5, the Gilbert equivalent ball is the Vapour). Both the size 4 & 5 rugby balls use the valve in-seam bladders.