This weldless sight glass is 11 or 16" long and works great on stock pots. Simply drill a 7/8" hole in your kettle and screw on the weldless bulk head. These are made of stainless steel and are easy to install. Please choose the length above. This sight glass also includes the 6" probe Thermometer so you can easily add a sight glass and probed to your mash tun or kettle and only need the one hole.