Bourns 2027-35-BT1LF is a 2-pole gas discharge tube with 350V DC sparkover voltage and 10kA impulse discharge current rating. It comes in an axial cylinder through-hole package.
The Littelfuse Inc. SL1021A230R is a Gas Discharge Tube Arrester with a 230V nominal breakdown voltage and a 10kA impulse discharge current rating. It features through-hole mounting.