If you want to put the Category III on your clothing you can have a few options at Redbubble:

Redbubble:

• Big black triangle
• Smaller black yriangle
• Red triangle

Teepublic:

• Black triangle, no text
• Empty triangle, no text

Transparency: I am neither of the sellers but I have just bought the smaller black one and will be wearing it to see Enter The Dragon later.