Hiro杉 Keiki PTFE Teflon Washer TT-0510-10 [300 pcs] Unused

Thank you for viewing.
These are PTFE (Teflon) washers from Hirosugi Keiki.
As indicated on the packaging, there are 300 pieces included.
They have been stored in a dark place, unused and unopened.
(While the label on the packaging shows some age-related color changes, the product itself is in excellent condition with no noticeable deterioration or discoloration.)
These are very high-quality fluoropolymer washers with excellent heat resistance, chemical resistance, low friction, and electrical insulation properties.

? Manufacturer: Hirosugi Keiki Co., Ltd.
? Model Number: TT-0510-10
? Product Name: Washer / Spacer
? Material: PTFE (Polytetrafluoroethylene / Fluoropolymer - Teflon)
? Specifications: Heat resistant, chemical resistant, low friction, electrically insulating
? Dimensions: Inner diameter 5.5mm / Outer diameter 10.0mm / Thickness 1.0mm
? Quantity: 300 pieces
? Color: White / Milky white

*As these are long-term storage items, they are listed at a significantly reduced price from the original retail price.

[About the Condition]
These were purchased over 10 years ago (believed to be around 2010 based on the label).
They have been stored in a dark place, unopened. As shown in the photos, they are in excellent condition with no noticeable deterioration or discoloration. However, please purchase with the understanding that these are long-term storage items.

■ Shipping
They will be shipped via Mercari便 (Mercari delivery service) in simple packaging.
Would these high-quality Teflon washers be suitable for DIY projects, model making, RC cars, or maintenance parts for machinery?
Immediate purchase is welcome. Thank you!