Qty two #041 (1/16" thickness, 3" I.D.) Buna N70 O-rings. These O-rings fit into the groves on both ends of KTM-Husqvarna-GasGas TPI & TBI aluminum silencer cans (2020-2024). Note stock silencer cans only utilize this O-ring on the inlet side; however, we have found that the same grove on the outlet side of the can will also accommodate this O-ring & helps reduce perimeter leakage on the outlet as well. Note these will work with Gen. 1 thru Gen. 2 of our spark arrestors but are only included with the purchase of the Gen. 2 model.