19 brand new panels. Measure 2ftx2ft for a total of 76 sqft.
This is Watts Radiant SmartTrac Standard SubFloor Panels (previous version with foil on top)
2 ft. x 2 ft. for 3/8 in. Tubing,
Watts Radiant’s SmartTrac™ is a non-structural, modular board designed for subfloor,
wall and ceiling radiant heating and cooling applications. It is manufactured from
5/8" (15.88 mm) thick MDF (medium density fiberboard) and is designed for use
with 3/8" (9.5 mm), ASTM F876 PEX or ASTM F2623 PERT.
They normally sell for about $27 per piece.
Here is the link
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