Blue Diamond® Gel pad is 10"W x 11"L and is 1/4" thick. It is about 5" wide and 8" wide at the tail. It can be cut to size as our gel is a solid not a liquid. It will not leak, ooze, or evaporate. It is designed to be inserted permanently within the seat or attached to the top of the seat.Hundreds upon hundreds of satisfied user claim "NO MORE NUMB BUM".