Normally bus couplers are available with 1.4:1 transformer ratios and 59 ohm (2 watt 1%) resistors.
For special applications, couplers can be supplied with different transformer ratios (e.g., 1:1) and other resistance values (e.g., 54.9 ohms).
Alternately, internally single-terminated couplers (with or without the non-functional bus connectors) can be supplied.
RFI dust caps (with or without safety chains) are recommended for all unused stub ports.
Data bus couplers are readily available in 2 through 8 stubs and in various sizes and shapes of boxes and slim inline models.