What is the difference between the P80318 and the P80318X?

What is the difference between the P80318 and the P80318X?

The P80318 is the Differential TDR probe. The P80318X is the P80318 Differential TDRprobe plus an additional probe body. The advantage of ordering the P80318X is that you would have a backup probe body for when the first one needs to be sent in for service.

Both the P80318 and P80318X,  are shipped with the same accessories; one set of two precision SMA cables, soft storage case, user manual, and three replaceable ground shorting straps.