The Diamond RH951S is described on the Universal Radio site as "... a triband antenna for 2 meters (144), 70 centimeters (440) and 23 centimeters (1200). It terminates in a male BNC plug. 50 ohms. It is a slim, black flexible antenna that is 15 inches long."
It's too long for me; I have a Diamond on the VX-6, and in the car it is a PIA. W2GLD suggested a Watson W-801 (from ScannerMaster, a sponsor of this site). I don't have the tools to measure its performance over the stock -106 duck and RS 800 MHz, but IMHO it seems to hear more signals when I swap antennas around. It is sturdier by a long shot. The W-801 claims coverage of 25-1900 MHz, just 2 inches longer than the -106 duck.
Hope this helps.