BUNA rubber bead lock o-rings. 1.8mm MOST COMMONLY used on bead locks that nearly bottoms out on wheel, i.e. (DWT, OTK/Tony, AMV, CRG, GP, Aluminos & more+). 2.4mm typically used on larger KNURLED beadlocks, Freeline, ART/Birel, etc. Sold in 12-packs.
