HQ5 head will not correctly engage with the spindle on a shaver model designed for an HQ3 or HQ4 head, due to a small extra piece of plastic in the centre of the HQ5 drive socket. Care should therefore be taken when choosing replacement parts. See also Philips Consumer Lifestyle References External links Philips shavers official website Teckjb Philips products Products introduced in 1939 Shaving Dutch inventions