Betamax refers to grilled blocks of coagulated chicken or pork blood. The name comes from the resemblance of these dark, rectangular slices to the shape and color of Betamax video tapes, which were popular in the 1970s and 80s.

The blood is collected to make Betamax, allowed to form into a solid, then sliced into rectangular pieces and skewered. These skewers are seasoned, grilled over charcoal, and usually enjoyed with vinegar, chili, or other dipping sauces. It’s a portion of affordable and popular street food, commonly sold alongside other barbecue items like "isaw" (grilled intestines) and "Adidas" (chicken feet).