DRUMCLENE BETEX motor garage product promotional enamel badge (early 1980's)

Postage is extra:

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For sale is a promotional badge issued to promote Drumclene's BETEX products.

I understand that BETEX was an exhaust fumes extraction system used by car mechanics and motor service/repair/testing garages. If anyone knows more information about this, I'd be grateful to hear from you. Thank you.

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DESCRIPTION:
Size: 1 7/32" x 29/32" (31mm x 23mm)..
Material(s): Brass metal with 1 enamel.
Finish: Nickle plated?
Fitting: Rollbar pin.
Imprint: None.
Approximate age: c.1982

CONDITION:
Very good condition. Pin in good working order. Minor scratch marks on surface but these noticeable only upon close examination and at certain angle to the light.
Please see photograph(s), these form part of the description.

POSTAGE:
* Postal costs are extra, additional to the Asking Price
* I always get a proof-of-posting certificate.
* I combine postal costs for multiple items when these are paid for and posted the same time.

RETURNS:
* Return accepted if the item(s) is returned in same condition it left me, then the full Agreed Asking Price will be refunded. Postal costs are not refundable.
* Buyer pays the return postal costs - unless agreed otherwise.

B.28