These high quality body grommets are commonly used by Track for both electrical and water pass throughs.
 
Available is various sizes, the M# refers to the hole size in the panel you are fitting the grommet to.
 
M12 - Material thickness up to 2mm (cable 4 to 7mm)
M16 - Material thickness up to 4mm (cable 5 to 9mm)
M20 - Material thickness up to 4mm (cable 8 to 12mm)
M25 - Material thickness up to 4mm (cable 11 to 16mm)