I bought this from Amazon a couple months ago via this product page: Amazon.com: MOTO-D Motorcycle Oil Fill Cap (20x1.5) - Suzuki GSXR 600 750 1000 SV: Automotive

Lo and behold, it doesn't fit my SV650. Looks like it's the size for GSX-Rs or any bike that has a 20x1.5 drain bolt. It is new, out-of-box. Never installed, as it doesn't fit my bike. It's pre-drilled for safety wire, so it's great for anyone looking to get on the track and is too lazy to drill-out their own drain plug.

Amazon sells it for $19 + shipping. I'll take $15 and meet anywhere in a 30 min radius from Manchester, NH.