This is a set of two IVANKO screw dumbbell bar collars and two spring collars of an unknown manufacturer. These spring collars could be attached to IROTEC and IVANKO shafts and used without any problems. *Please see my profile for details regarding transactions. *Please purchase only if you understand that these are used items and may have minor scratches, etc. IVANKO, IROTEC, LEADING EDGE, dumbbell, barbell, plate, shaft, weight training, home gym, training equipment, adjustable, weight, rubber, paint, iron, steel