An agricultural baler comprising a main bale chamber having a pair of opposed side walls, with each side wall having a plunger slot arrangement defining a plunger slot. Each plunger slot has opposite ends and is open at an inside adjacent to a plunger. A pair of rotating elements are positioned within each plunger slot, with each rotating element being located at a corresponding end of a respective plunger slot. A pair of plunger slot belts are each positioned in association with a respective plunger slot and partially wrap a respective pair of rotating elements associated with each plunger slot.