The Sanitaire 541741 bag adapter fits the outer bag assembly on Sanitaire Tradition series commercial upright vacuums, including models SC679, SC684, SC881, SC886, SC888, and SC899. It is also compatible with Eureka models C2094D, C2094E, C2094F, C2194A, C2194B, C2031B, C2031BM, C2031D, C2031E, C4046B, C4046D, and C4046E. Replace when the adapter is cracked or no longer seats the outer bag properly.