When belt pulley alternator performance matters, the AS-PL AP4004 delivers — built to the same dimensional and material standards as the original part it replaces. The part is built to the following specification: Quality: STANDARD LINE, Outer Diameter 1 [mm]: 66, 80 mm, Inner Diameter 1 [mm]: Fibreglass, 00 mm, Inner Diameter 2 [mm]: 53, Brass mm, Number of grooves: Copper. Each dimension is checked against the OEM reference to ensure the component seats and functions correctly first time. This part supersedes original equipment references: 051.000.816.106, 134518, 1668894, 24188 and 83 more. Matching these numbers confirms a like-for-like replacement with no loss of function. AS-PL is a recognised supplier of automotive engine timing components to independent workshops and dealer networks across Europe. All parts are sourced from authorised distribution channels and carry full manufacturer traceability — you receive exactly the same component supplied to professional garages and dealer workshops. If fitment or specifications do not match your vehicle, our technical team can help identify the correct alternative — use the vehicle selector or contact us with your VIN for a guaranteed-fit recommendation. Replacing worn components on schedule preserves your vehicle's safety, reliability, and resale value — and aftermarket parts from established brands deliver OEM-equivalent performance at a fraction of the dealer price. Every part is dispatched with tracked delivery and a 14-day money-back guarantee with hassle-free returns.