For selecting a temperature sender, what information should I have before contacting a distributor or sales rep?

What temperature range do you need (eg: 100-240°F)

What thread size do you need (1/4" is standard and a universal kit is available containing adapters for 1/4", 3/8" and 1/2" pipe threads, metric adapters are also available)

If you wish to try to match an existing gauge, what is the resistance range (ohms) of the current gauge (see question on mixing Stewart Warner and non-Stewart Warner instruments and senders). Your distributor or sales rep can assist you with this if you have the gauge brand and part number

Do you need to run two gauges with one sender

You should also provide information on the temperature gauge you will need by following the guidelines in "Selecting a temperature gauge".