Glass can slightly vary in size and in fitment due to its nature. We do however include a way to ensure all our glass will fit your device. If you look inside of the Bolt kit that you ordered, you will find a little packet with 2 spare large o-rings and 2 small o-rings. If you take the 2 small o-rings and place them in between the two large o-rings already on the device it should make the connection tight between the glass and the ceramic heating top! If your glass is still a little loose, try placing the small rings under the large ones on the device. This will make more loose fitting glass snug.