Purchased probe and found it to be outstanding; used last week on large tri tip with mini WSM. Question was asked about size of grommet required. The outside diameter of probe collar is 3/8 inch. Did not work with Cajun Bandit 3/8 grommets because the inside diameter of the grommet is .315 inches; not .375 inches. Now using 3/4 in. x 1/2 in. brass MIP xFIP Hex bushing with nut. Removed 3/8 grommet and enlarged hole with step drill. I have found three solutions for high temp silicone grommot upgrades for older WSMs and any Weber kettle. High temperature rated grommets for Weber Smokey Mountains, kettles, and stacker conversions with 1/16 inch panel thickness are: Weber 85037 Grommet which requires a 1 1/4 inch cut hole; Mil Spec 5 Grommet, Silicone, 3MRT1 which requires a 13/16 inch cut hole; or Mil Spec 5 Grommet, Silicone, 3MRR9 Grommet which requires an 11/16 inch cut hole. I highly recommend the use of a high speed steel step-drill and lube for cutting the hole; excellent USA made on eBay. The 3MRR9 grommet is the lowest cost option since you will be getting a package of five and it has the smallest drilled hole with 7/16 center hole for inserting your probes. The next recommendation is the 3MRT1 grommets (pkg of 5) and has a 1/2 inch center hole for inserting probes. All items can be found on eBay.