This is a Boom Racing non-flanged nylon lock nut m4 (5) Click on the link to view more information.
Product safety information
Manufacturer information:
Boom Racing Ltd.
945 E Juanita Ave ST 109
Alabama
Mesa, Vereinigte Staaten, 85204
sales@boomracing.com
Responsible person:
Crawlermanufaktur
Karl-Schurz-Weg 18
Solingen, Deutschland, 42657
info@crawlermanufaktur.de
https://www.crawlermanufaktur.de