I'll catch you on the download!
It is a silver bracelet with yellow ornaments on it. There is an orange gem in the center from with the energy emits.
In "The Flying School," Helia receives the weapon.
In "The Curse of Fearwood," the weapon is seen again, being used against the werewolves.
#124: Attack of the Centaurs
Helia uses his Rose Thorn Bracelets to help back up the Winx by attacking the Centaurs as the girls made rescuing the panicking fair-goers their main priority. He blasts down a Centaur alongside Sky and his Moon Khukuri.
It fires yellow-green thorn-like rays of energy.