These are 4" long 18lbs rated zip ties, great to small diameter harnesses like the one on your headunit.

These high quality Install Bay brand zip ties I buy from Metra. The same quality zip ties most install bays use across the USA. Do not be fooled into buying cheap zip ties that break from other online venders, these are the good ones you want to use in your installation.

These are sold in prepackaged bags with 100 zip ties per bag.

NOTE: The sticker on the packaging has changed slightly from the picture, but these are still the same quality zip ties.