This very fine1 micron grade is only for beer that has fallen very clear, and fining with Instant Isinglass is recommended before using to prevent clogging the filter halfway through a 5 gallon batch. Recommended for experienced filter users. These 8.75" diameter pads fit our Q73 Plate Filter. These are disposable - you will need two pads per 5 gallon batch of beer. Made by Gusmer in the USA.