StairRail/Guardrail Gauges (6", 4 3/8", and 4")

These are a great set of gauges to make sure you're up to safety guidelines/codes for your guardrail systems for your decks and stair railing systems.

According to the IRC, under the section: R312.1.3, here are the guidelines (paraphrasing):

A sphere no bigger than 6 inches can pass between the point between tread/riser and bottom of the stair railing

A sphere no bigger than 4 3/8 inches can pass between between two ballusters for stair rails

A sphere no bigger than 4 inches can pass between the ballusters at the guardrail system at the deck.

Here are two discs that will help!  You have your 6 inch sphere for the tread/riser and guardrail system for your stairs. 

You also have a disc that is two different sizes! 4 3/8 inches on one side and 4 inches on the other side (disc is marked).

Comes in medium gray (what you see in the pictures)