Serta PSX Knox Firm

Get the firm support you need with the Serta PSX Knox Firm. Featuring 5-zone support for full-body spinal alignment, Perfect Conform™ Memory Foam, and a classic quilted feel, this mattress delivers solid support with memory foam comfort at an exceptional value.

Firm Support with Intelligent Design

The PSX Knox Firm combines firm, supportive comfort with advanced 5-zone technology that targets different areas of your body. Perfect for back and stomach sleepers who need solid support with the added benefit of memory foam pressure relief.

Advanced Features:

• 5-Zone Support System - Customized support for head, shoulders, lumbar, hips, and legs
• Perfect Conform™ Memory Foam - 1" layer provides pressure relief without sacrificing firmness
• Firm Comfort Level - Solid, supportive feel for proper spinal alignment
• Classic Quilted Top - Traditional quilted surface for timeless comfort
• Responsive Coil System - Reliable support with classic innerspring feel
• Full-Body Spinal Alignment - 5 zones ensure proper support from head to toe
• Memory Foam & Cooling Upgrades Available - Customize your comfort
• Serta Quality - Over 90 years of sleep expertise
• Fast Delivery - Available in as little as 2 weeks

Perfect For:

• Back and stomach sleepers needing firm support
• Those with lower back pain requiring targeted lumbar support
• Heavier individuals who need extra support
• Anyone who prefers firm, supportive sleep surface
• Budget-conscious shoppers wanting 5-zone technology
• Those transitioning from very firm mattresses

Firm vs. Plush - Which to Choose?

Choose Firm if you're a back or stomach sleeper, need maximum support for lower back pain, or prefer a solid, supportive feel. Both models feature the same 5-zone support system - the difference is in the comfort level on top.

Experience firm, intelligent support with the added comfort of memory foam. Quality sleep at a price that makes sense.

Available in all sizes | In stock and ready to deliver