rigsize

East to West Blackthorn 3750LK mattress size

Years 2026Sold as BlackthornLength 40' 10"Sleeps 4
70 in 80 in
To scale. Dashed: a regular queen.
Main bed70 × 80 inRV king

That's an RV king, 6 in narrower than a regular king (76 × 80 in). A regular king won't fit, so get an RV king in exactly 70 × 80 in.

About the RV king size →

East to West spec page, 2027.

Mattresses in 70 × 80 in

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Great all around
RVMattress.com Signature Hybrid

RVMattress.comSignature Hybrid

  • Hybrid
  • 13.25 in thick
  • Soft / Medium / Firm

Sleep Foundation: Best Mattress Overall Read review

$1,865RV King - 70x80 · list priceSee price
Best value
RVMattress.com CopperFlex Essential

RVMattress.comCopperFlex Essential

  • All-foam
  • 6 in thick
  • five comfort options
$799RV King - 70x80 · list priceSee price
Firm
RVMattress.com Plank Firm Luxe

RVMattress.comPlank Firm Luxe

  • Hybrid
  • 13 in thick
  • Firm / Extra Firm
$1,865RV King - 70x80 · list priceSee price
Cooling
RVMattress.com Aurora Luxe Cooling

RVMattress.comAurora Luxe Cooling

  • Hybrid
  • 13.25 in thick
  • Soft / Medium / Firm

Sleep Foundation: Best Mattress for Temperature Regulation Read review

$2,465RV King - 70x80 · list priceSee price
RV hybrid
RVMattress.com CopperFlex RV Hybrid

RVMattress.comCopperFlex RV Hybrid

  • Hybrid
  • 10 in thick
  • Medium-Firm
$1,065RV King - 70x80 · list priceSee price
Custom size
Mattress Insider Luxury Gel Memory Foam

Mattress InsiderLuxury Gel Memory Foam

  • Memory foam
  • 8 in thick
  • not stated
Made to 70 × 80 inGet a quote

Is this your 3750LK?

Check the year and length against your RV before you order.

YearModelLengthSleeps
2026Blackthorn 3750LK40' 10"4

Other Blackthorn mattress sizes

Sources

  1. funtownrv.com: https://www.funtownrv.com/product/new-2026-east-to-west-blackthorn-3750lk-3572648-5

Questions

What size mattress is in the East to West Blackthorn 3750LK?

The main bed is 70 × 80 in (East to West spec page, 2027).