The HF-2 is combining the original signal with a delayed signal that is shifted one octave up to create a flanging effect a bit different but still similar to the BF-2. The effect is brighter and cleaner than the BF-2. The HF-2 may not be as powerful as the BF-2, but for hi frequency flanging it produces a very good result.Vintage Boss Flanger, made in Japan in the'80s. Paint is cosmetically rough but due to the classic rugged boss construction has no effect on function or sound. Was originally ACA power, requiring an annoying 12V but has been converted to PSA, requiring only 9V. This change is purely functional and does not affect the sound as the original method steps the 12V down to 9V before it hits the effect circuit anyway. This item is in the category "Musical Instruments & DJ Equipment\Guitars & Basses\Parts & Accessories\Effects Pedals\Flangers". The seller is "squarewavefuzz" and is located in this country: GB. This item can be shipped to United Kingdom.