Gurfateh veer,
You miss heard slightly he was refering to a seli topi which is a loosely woven "hat", which was worn by the first 5 gurus and was an important part of early "sikhism" be it without the offical name since this was established by the 10th guru. Dastars 1st started to be worn after the 6th guru command that turbans should be worn, and i believe after which baba buddha ji started to wear a dastar instead of a topi.
I am reasonabily sure of this infomation after conducting some research however it I can not be sure 100%.
Hope it helped
Satnam