Check the listing for details. 415 Chain Master Link Bicycle Engine Kit Replacement Part Motorized Bike. Color: Silver, Condition: New. Listed at 2.95 USD. Designed to provide drivetrain versatility, the 415 Chain Master Link will make installing your chain easier than ever. Due to the wide variety of bike frames compatible with these engines, installing your chain can require modification. This requires the use of a chain breaker which as a result to using it, will leave your chain incomplete and needing a link to complete it. This is where the master link comes into play, by installing it to the missing section of chain, you can successfully install your chain after being altered. Not to mention installation is easy, simply align the pinned section of the master link between the two broken links, install the oval-shaped end to complete the link, and finally install the clip to secure the link. So, whether you are adjusting your chain or repairing a damaged chain, you can trust that the 415 Chain Master Link has you covered.