Abstract: Fuel cap with a see-thru top that is both functional and decorative. The fuel cap body made from billet aluminum, plastic, or completely acrylic is like any stock fuel cap for that application. Oriented as a inverted hollow cup with inner female threads that allow it to be placed on a fuel tank filler opening with matching male threads. Centered at the top of the cap is a round hole that accepts a clear lens made of any glass or acrylic, poly, fuel-resistant material. This lens has a beveled top so it can be placed into the fuel cap body from the top and secured from the inside with a Viton O-ring. Using this method retains the clear lens in place and also seals the mating surfaces preventing fuel leakage. Protruding from the top center of this clear lens is a nipple with a knurled end. Bored vertically thru this nipple is a vent hole that allows fuel tank venting and positive/negative pressure relief. A vent tube is attacted to this nipple on one end and can be routed to vent overboard.