The Aerozine alloy headset cap weighs only 7g including bolt and features an extra light weight CNC machined top cap, with an aluminum M6 bolt, saving up to 11 grams over a generic alloy top cap with steel bolt. The cap itself is not much heavier than a carbon fiber top cap, much of the weight savings comes from replacing the steel bolt with an aluminum one which is 1/3 the weight. This bolt is non-structural, and only serves to lightly pre-load the headset before tightening the stem, and to keep the top cap on. It features a more attractive design than the J&L Top Cap, but a worse value. At $10, and saving 1g per dollar, it represents can acceptable value, low cost upgrade. It can be purchased on eBay.
Price: $10 [Low Cost]
Value: 1.1g/$ ($0.90/g) [Acceptable Value]
✘ Not Recommended
The J&L top cap is half the price and only 1g heavier, making this only an acceptable value in comparison to a generic top cap. On the margin, that extra 1g of weight savings for an additional $5 (0.2g/$, $5/g) represents a very poor value. Only get this is you prefer the aesthetics.