A solid roller (non-O-ring) clip-type master link chain. Depending on the specific motorcycle and K series you have will dictate whether you need a 428 or 520 pitch drive chain.
428 Pitch Drive Chain
CB175 K0 - K5
CL175 K0 - K5
SL175
520 Pitch Drive Chain
CB175 K6* - K7
CL175 K6* - K7
CB200
CL200
*It is possible that some early K6's have a 428 size chain/sprockets whereas other K6's have 520 size chain/sprockets due to a change in the Honda Factory.
Parts you might need:
