Rated at 280W and testing at 267W in perfect cold sun has these operating at 95% of their label. You can see this on the output of my Fluke meter, it even adjusts for cell temp and irradiance. These panels are used and come with a 1 year warranty from Beene Brothers. They are located at my warehouse in Mansfield, TX.
I can freight if you need at least 10 panels, send me an email and I can get you some numbers.
Model number STP280 – 24/Vd
Cell type is Poly-Crystalline
1956 × 992 × 50 mm (77.0 × 39.1 × 2.0 inches)
Weight 27.0 kgs (59.5 lbs.)
Glass is tempered for maximum impact resistance
White back sheet
MC-4 Male and Female connectors with ~3′ leads