King Electric is the first to market with pre-terminated self-reg kits in 125 and 150 foot lengths.
King Electric SRP Electric 120 Volt Pre-Assembled Self-Regulating Heating Cable. Roof & Gutter Deicing or Pipe Heat Trace. From 6 foot up to 150 foot lengths
They have also increased their stated wattage to 6 w/ft. per their new literature.
https://morelectricheating.com/products/ROOF%20AND%20GUTTER%20DEICING/KING%20SRP.aspx