5 pcs LM338T 1.2-40V adjustable voltage regulator, 5 Amps. This is the most capable LDO linear voltage regulator in a TO-220 package.
The output voltage is defined by the ratio of 2 resistors, multiplied with the internal reference voltage of 1.24V (please refer to the datasheet, available online).
This voltage regulator is designed for heavy loads, and it supports start-up currents of 7A, with peaks of up to 12A (internally limited). This voltage regulator is not designed for high-precision power supplies and for applications where a very low ripple is required. It is a work horse, not a hummingbird.
Please note, LM338 is an older device, produced by different companies like National Semiconductor, Linear Technology, Texas Instruments and others. We can’t guarantee a certain branding on these chips. Therefore, the shown ICs on the picture are generic.