Koopman - Chess set - Wood

A very beautiful, well-working Koopman chess clock.
Koopman clocks were known for their:

Massively wooden housing – usually beech or oak wood, with a classic, angular shape
Fully mechanical wind-up movement – no batteries needed
Clear dials with red flag indicators for precise timekeeping
Precision-driven tempo – each clock could be adjusted for perfect synchronization
Patent 65843: The flag of precision
One of Koopman’s proudest technical contributions was Patent No. 65843 — clearly indicated on many of his clocks. This patent likely referred to the improved red-flag mechanism and the enhanced construction of the time-switching system.

Collectors today recognize "Patent 65843" as a mark of authenticity — indicating that it is a piece built during Koopman’s most refined production years.

This clock is from after 1972, as seen by the copper back of the clocks; older clocks had metal backs! hxbxd 13x23x7cm

This clock is shipped in the original box.

The proceeds are intended to support the mentoring of chess talent at a club."