Package of (1) Dyson DC17 belt 8mm wide belt. The 8mm wide version of the DC17 belt is designed to replace these original Dyson part numbers 911710-01 and 11710-01-01. The 8mm wide belt will fit all Dyson DC17 models, including models that us the 10mm wide belt. Replace this belt every 6 to 12 months to ensure optimum performance.