Firehouse Vape Lemon Blast - Lemon Tart. Just like an old school Lemon Tart with its tangy citrus lemon rolled into a shortcrust base. The sweet refreshing lemon blasts through your tastebuds followed by the exquisite baked aroma.. Available in 3 strengths 3mg (50VG/50PG), 6mg (60PG/40VG) and 12mg (60PG/40VG).