This is a 42 MHz Oscillator. All Accelerator Boards use Oscillators to control how fast they run. You can generally increase your speed by replacing the existing Oscillator with a faster one.
You may also need a new CPU and Static RAM to allow your Accelerator Board to achieve higher speeds.
Accelerator Boards take the Oscillator speed and divide it by four (4). This Oscillator will allow your Board to run at 10.5 MHz.
Note: Installing a faster Oscillator then what your Accelerator Board was designed for may cause it to lock up randomly, not boot or other unpredictable and strange errors. This is not due to a defective Oscillator. No damage can occur to your Accelerator Board from your system locking up UNLESS you install the Oscillator incorrectly. Generally we recommend running GS/OS for 15-20 minutes and then letting it stand 'idle' for 15-20 minutes. If your IIgs passes this test without locking up then there is a good chance you will not have any issues with the faster speed. We have also compiled a guide to help you in over-clocking your TWGS >HERE<.