Attached to a backer rod to complete the insertion tool, the Albion 640-G04 Wheel Accessory is made from standard, high-quality plastic with a good amount of durability.
The plastic insertion wheels are used on sensitive substrates like glass, aluminum, or EIFS. They exclusively can be used with 640-4 and 640-5 insertion tools and not the 640-6 models. The wheel has a diameter of 3/8�. The 640-4 rod model kit has an epoxy filled reinforced handle to withstand rough surfaces and is paired with this 640-G04 Wheel Accessory that sets foam backer rods in caulk joints at a consistent depth without puncturing anything. This wheel is used with other wheels as well viz., the G40-G03, G40-G02, and G40-G05 wheels.