Where can you get it and what exactly is it?

Tylose from Nick Lodge: http://www.internationalsugarart.com/cgi-bin/store/shop.cgi?ud=RTlWWVEwVDcySiUlJSUlJTExODcwNTE5MDkA&storeid=1&sortby=categories&searchtext=tylose&cols=1&&c=detail.htm&itemid=TP105

Tylose from Country Kitchens: http://www.countrykitchensa.com/catalog/product.aspx?T=1&productId=619070

Tylose is an alternative to gum tragacanth. Both products act to make whatever it is added to harden faster or provide stability. (Kinda like a thickener).