Clarathon Spa Filter Replacement for Hot Spring Tri-X 73178, 0969601 Dual Core Antimicrobial Reusable Filter Replaces Mfg. #31489, 75041, 73178, 0969601 6" W, 10-1/2"L, 1-15/16" openings in each end Replacement for Tri-X filter cartridge - Premium Quality STOCK UP & SAVE!!