What are the Three Special Parts of the Boy Scout Uniform?

The Boy Scouts is a youth organization that currently boasts nearly five million members.  It classifies them into separate divisions based on age, with the Cub Scouts being the youngest.  The Cubs program consists of several divisions itself.  Boys who make it to the final rank, Webelos, must pass a series of tests in order to advance to the Boy Scouts.  One of the tests consists of naming the three special parts of their uniform.  

Hat

The first special part of the Scout uniform is the hat.  Webelos wear hats similar to their older and younger counterparts in that they display their troop number, with the main difference being the color and pattern.  A Webelos hat features a plaid design as well as the Webelos insignia and is to be worn at all times when its owner is in uniform.

Neckerchief

Webelos Scouts have the option of wearing either a Cub Scout uniform or a field version of the Boy Scouts.  Regardless of the one they choose, their ensemble must include the Webelos neckerchief, a plaid accessory that features the den's emblem and matches their iconic hat.  The neckerchiefs are worn under the collars and are typically presented at ceremonies.  

Neckerchief Slide

The final component of the Scouts uniform is the neckerchief slide, which is necessary to secure the Webelos neckerchief.  The items are gold colored and feature bright blue colored Webelos emblems.  The slides are extremely important parts of the Webelos ensemble and, just like with the Webelos plaid neckerchief and hat, a scout who shows up to a den meeting or other sanctioned event without his is considered to be out of uniform.