These are old pyrometric cones from the inventory of Seeley's. Only random cone temperatures remain, but the price can't be beat!
Choose the type and temperature (listed for each type from coolest to hottest) cones you want from the drop-down menu above.
Junior cones (item starts with SRB; 50 cones per box): Junior cones are designed to be placed in a kiln sitter in a kiln. Junior cones control the temperature at which the kiln turns off. Junior cones are the 4 small cones shown in the middle of the photo.
Large cones (item starts with SSB; 25 cones per box). Also called witness or self-supporting cones, the large cones are designed to be placed on the shelf of a kiln to indicate when the desired temperature has been reached. Use witness cones in every firing to determine whether your firing was successful. The self-supporting witness cones are the large cones shown on the outside ring of the photo.