What on earth is this light for? 737 question (update w/ pic)

This subreddit is for all aviation maintenance technicians and enthusiasts of the inner workings of aircraft. Please see r/aviationmtcSALES for purchases/sales.

I really want to know what controls this light 737... No one knows!!

We are the Original unofficial Boeing subreddit for anyone interested in The Boeing Company. Here you can share videos, pictures, news articles; anything related to Boeing!

What's the biggest promise you've ever broken?

r/AskReddit is the place to ask and answer thought-provoking questions.

Any recommendations for where I can get some good acrylic yarn? I can't find good quality.

The little sister to r/crochet & the place to get all the crochet help you need! Please remember: internet friends are not your personal search engine. The community expects that all members put in some initial effort to read and learn before seeking help. The r/crochet wiki has a wealth of information. Read it first — moderators and members spent a lot of valuable time putting it together. Do a search of this subreddit, so as not to be repetitive. If you still need help, we’re here!

They keep curling for some reason! How to prevent it in flat pieces??

The little sister to r/crochet & the place to get all the crochet help you need! Please remember: internet friends are not your personal search engine. The community expects that all members put in some initial effort to read and learn before seeking help. The r/crochet wiki has a wealth of information. Read it first — moderators and members spent a lot of valuable time putting it together. Do a search of this subreddit, so as not to be repetitive. If you still need help, we’re here!