A low mass finger piece that's a frequently overlooked "feature" of the KungsImport sideswiper which was sold through "QST" in the early 1980s, it minimized the hacksaw blade chattering when the contacts were closely spaced from the key lever (blade).

From W1TP.com website:

Aluminum mechanism on wood base with hacksaw blade armature & wooden knob. 3 Suction cups on bottom of base. Label reads: FIRMA KUNGSIMPORT, Box 257, 434 00, KUNGSBACKA, Postgiro 9 10 99 Sweden. About 200 of these keys were made in the late 1970s by Hank Svard a Swedish Radio Operator at the SAG Goteburg Sweden shore station and his friend, Bengt-Arne Jockert / SM6CKU. About 50 of them were sold to Americans. He writes that his key business did not thrive so he had to keep on working at SAG. He said "it was a thrill at the beginning of every watch to caress the wooden handle. The ability to switch between sending very very slowly or very very fast made you feel totally in command. You created your own style and therefore you were greeted by name by the other ships calling in". The suction cups were notorious for losing their suction causing the key to suddenly and surprisingly drift across the operating table.

Photos are of my KungsImport sideswiper, QST ad for this key, a photo of SAG Goteborg Island Radio Officer, Hank Svard (SK), a photo of Hank's well used key, notice the suction cups which attempted to keep the key held down, a frequency list sticker sent to ship radio officers in ports, and old SAG and newer SAG QSL cards.

73
DR