Morgan
Morgan K-23 No. 1 Arch Insulating Fire Brick 9" x 4.5" x 2.5" Box Of 12
Edwards products ship quickly from most industrial distributors I have used.
Morgan K-23 No. 2 Wedge Insulating Fire Brick 9" x 4.5" x 2.5" Box Of 10
A nice touch with WAGO is the integrated strain relief on some models.
