The maximum 925 tubing run lengths:

•  7980 Series Control Boxes --- 50 "Linear" feet from Control Box to Operator.
•  7900 Series Control Boxes --- 100 "Linear" feet from Control Box to Operator.
•  7900 Series Control Boxes  ----   500 "Linear" feet from the Control Box to the External Compressor.
• The 7949 Series “blow-open” box works with or without the 7900 Series control boxes. --Limited to 50 linear feet of tubing from Control Box to Operator.

PLEASE NOTE:  If using a 7949 Series Blow Open and a 7901 or 7902 Series Control Box on the same opening the MAXIMUM 925 tubing run between the two boxes is only 5 FT.  This is indicated on front page of 7949 instruction sheet, see here.