Electronic – What kind of knob fits a slotted potentiometer shaft

Some rotary Pot's com in Linear, Audio and reverse Audio (where audio=log taper)

Actually it is "quasi"-log scale and not precision logarithm.

Notice it has a rapid transition from two different linear slopes. which gives you more sensitivity over a wider range of audio inputs rather than an apparent Off to ON effect if using a linear pot. If one adjusts audio equipment over a 30 dB range, that might occur in the 1st 5% of a Linear pot.

Such as

Many options may be selected when you order.

Precision Log pots would be mcuch more expensive than

The rotary switch under discussion is typically used for preset / factory setting or maintenance purposes - such as for setting a part of a device address, a configuration value to be read during device operation, or selection of power path for enabling one of several circuit sub-sections.

The particular part you have selected has silver-plated copper contacts (Q suffix) for power routing, rather than low-level signal routing or configuration setting.

The lack of available knobs for this type of switch aligns with the design goal of not making it convenient for end-users to make changes - like having a sticker "No user-serviceable parts inside".

For a hand-actuated equivalent, look for flatted actuator, or knob actuator designs. Some thumbwheel actuated designs are also very cost-effective, especially on eBay or other such sites.

A quick search indicates you may be able to find thumbwheels cheaper than the device you have selected, if 10 positions are not a firm requirement.

Another reason for going with thumbwheels is that they are less obtrusive than knob / shaft devices, hence allowing sleeker enclosures!