An operation device includes a rotatable operation panel and a tilt mechanism including a recessed groove and pawl member capable of engaging with the recessed groove and an urging member configured to elastically urge the pawl member. In the first stage, the RF signal is mixed with both components of the local oscillator signal in a sub-harmonic mixer to produce an intermediate frequency output signal having a frequency component at twice the local oscillator frequency minus the RF frequency, i. Instead upper and lower slots are cut into the sleeve, and the rings are pressed or otherwise tightly fitted into each slot. Information types can include descriptive textual information, visual information, and auditory information about the property item and its owner or user. The improved flow circuits use basically only the typical HPLC system components, except for some insignificant modifications from existing injector designs. A hand-held power tool can drive the web assembly, adjustment of inclinations of the back and leg sections of the frame, and vertical motion of the lift arm.