The ISH 4R XL is a UK-made LED horticultural lighting kit from Invisible Sun built around the brand’s R Strip modules. Each strip uses Samsung LM301H white diodes with LH351H 660 nm deep red and 730 nm far red to harness the Emerson effect. At the R Strip’s rated maximum of 2.1 A, output is about 59.85 W per strip; configured as a four‑strip XL kit, typical combined draw is roughly 240 W. The flowering footprint referenced for this kit is about 3×3 ft, suitable for compact tents, with larger coverage in vegetative growth. Invisible Sun states LED lifetimes of 50,000+ hours on comparable kits.
