The precursor to modern passive protection for rock climbing and mountaineering use was the Piton or "peg". The smallest of which are knifeblades, for hammering into the narrowest cracks. Their use is generally frowned on in UK climbing these days, but they are often still used for winter mountaineering and Alpinism.
Piton for progression only (body weight) - it is not designed to hold a fall.
Weight: 48 g (8 cm length) Reference Size Type 65504 4 cm P 65506 6 cm P 65508 8 cm P 65510 10 cm P Material: chromoly steel 3-year guarantee CE / UIAA