Need help identifying button or plug

A quick learner from Pittsboro, NC says:
Hello,

I've ordered the following parts for my non-tilt windows and need help identifying the button or plug piece that plugs the holes towards the bottom of the window.

S800-21 : 21" Series 800 Channel Balance
18-036 : 1/2" Top Sash Guide
S800-17 : 17" Series 800 Channel Balance

The first picture is a view of the back of the button -- it's split in the middle. The second picture is a view of the button installed in the window.

The button is less than half an inch in diameter.

Please let me know if you have any questions which would help identify this item. Thank you for your help with this!
Thumbnail of the uploaded file named IMG_0123.jpg
Thumbnail of the uploaded file named IMG_0125.jpg
Profile picture of Tom
Tom from SWISCO responded:

Hello! My first thought was our 87-132 nylon button. Carefully review our dimensions and see if this could work as a replacement.

18-036 : 1/2
1/2" Top Sash Guide
18-036
$1.59
VIEW >
87-132 : Sliding Window Glide Button
Sliding Window Glide Button
87-132
$0.35
VIEW >
S800-17 : 17
17" Series 800 Channel Balance
S800-17
$14.37
VIEW >
S800-21 : 21
21" Series 800 Channel Balance
S800-21
$14.96
VIEW >
How to Repair a Jammed Window
How to Repair a Jammed Window
VIDEO
WATCH >
How to Replace a Top Sash Guide [1080p]
How to Replace a Top Sash Guide [1080p]
VIDEO
WATCH >
How to Identify Replacement Channel Balances
How to Identify Replacement Channel Balances
VIDEO
WATCH >
How to replace a channel balance
How to replace a channel balance
GUIDE
READ >
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)
Current wait time is 4-7 business days
We promise that one of our experts will personally get back to you as soon as they are able. Thank you very much for your patience and understanding. If your inquiry is time-sensitive, please feel free to reach us at 856-317-6263 or at help@swisco.com.