These are components use in MM XL can assembly.
Boost check works ONLY in GEN 5+ 'super center's
Breathers are correct for XL size 3.5" (not 3" Standard)
XL 3.5" Can Spare Parts
Returns: Allowed within 30 days and refund -15% restocking will be sent when the part arrives returned in new condition.
Replacement due to error or shipping damage: Will be standard shipping, and may include return label for supplied box to return wrong or damaged part.