Tilbury Irish style whistles are made in the U.S. by Chuck Tilbury. They're built from aluminum alloy; headjoints use a delrin plug with a curved windway. Tuning slides use easily replaceable rubber o-rings. Holes are slightly larger than commonly found to allow easier half-holing. The net result is a quality Irish whistle at a reasonable price.
Tilbury Whistles were previously sold under the GFM name (after Chuck Tilbury's previous home in the Granite Falls, Washington, area). Tilbury whistles show a number of design refinements.
Here's what Chuck Tilbury has to say regarding playing characteristics of his whistles:
"This instrument is ideal for people with moderate experience who want to step up to a higher-end whistle. These whistles are easy to play and are well balanced between octaves. They have a pure tone with just a hint of "chiff." Tuning is (of course) perfect and the instrument can be tuned a minimum of 20 cents sharp as well as flat. It plays with plenty of back pressure and it plays big enough for noisy venues, or for playing outside. This instrument has medium air requirements, and shifting between the high and low registers is very easy to control. The back pressure is firm and you can really "lean into" the instrument. The first 3 notes in the low octave are strong and clear, and there is very good balance between octaves. While not as powerful as a Chieftain or an Overton, it is loud enough for most sessions. Most cross fingerings are possible, such as C natural (on a D whistle) and in both octaves. This instrument is moderately loud, easy to play, and it is very responsive. It will comfortably handle any tap or roll that you throw at it."
