Overview Reviews Product Description 6/7PK 57.6mm billet idler with bearings. Used in various ESS BMW supercharger systems. Product Videos Custom Field Product Reviews Write a Review Write a Review × 6/7PK 57.6mm billet idler with bearings. Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *