These simple sleeves help keep elbows straight to improve volleyball passing or volleyball setting technique. Each lycra volleyball sleeve slides on the volleyball player for a comfortable fit. Removable Fiberglass resistance inserts offer 3 levels of volleyball training. Package includes two sleeves with removable resistance inserts. One size fits most. Tandem Sport has been manufacturing and distributing quality volleyball, sports medicine, equipment and training devices to the sporting goods market since 1989.