Dapol Smoke fluid Traditional and Dapol Smoke fluid Non Odour. Dapol have developed these fluids to produce a lighter, improved drifting effect than other oils currently avalaible on the market.
From Dapol Site:
I find this smoke oil far superior to the other oils on the market. Not only is the burn time greatly increased, but when in full flight, the smoke does drift well from the loco.