The 40-551 is a 10A matrix configured as an 8×4 matrix that switches voltages up to 125VDC and 250VAC and features an optional loop thru facility that simplifies user cabling when the matrix size is expanded through the use of additional modules. The 40-551 is also available in 8×2 and 4×4 configurations.
Both the 40-549 and 40-551 use high quality electromechanical relays (EMR’s) which offer long service life
US list prices range from $1214 to $1619 for the 40-549 and $1180 to $1785 for the 40-551.