The Hafthohlladung (lit. adhesive hollow charge) was primarily used by Wehrmacht tank killer squads. Around its base were three metallic magnets, each provided with a pair of pole pieces that were configured to act as stand-off feet with a strong magnetic field across their gap. This allowed the infantryman using the device to attach it magnetically onto the steel enemy tank, no matter the angle of the surface on which it was placed, before arming it by pulling the ignitor at the rear of the mine. Because the device blast axis was normal to the armour at the point of placement, the degree to which the tank's armour was sloped had no effect on the device's penetration. However, this requirement for direct placement made use of the device very dangerous to the infantryman placing it, as that infantryman would be highly vulnerable to enemy fire. The Hafthohlladung device itself was very effective against armour, being able to penetrate around 140 mm of RHA. The H3 (3 kilos weight) and the H3.5 (3.5 kilos weight) models can be easily distinguished; the 3.0 has a bottle shape while the 3.5 looks like an inverted funnel.