Master Cylinder Plug, 7mm/18mm 67-79. 211-611-817A 211611817A £2.50 inc. VAT (where applicable) Quantity: at £2.50 each Add To Basket 0 in your basket View Basket Checkout German made master cylinder bung. 2 required per master cylinder. 7mm inlet to 18mm outlet Correct all Bay window 68-79. Also fits 66-67 Split screen with dual circuit master cylinder.