One of the largest, based on sheer mass and size is the aptly named "Pig"; or the M60. While not the largest "hand held" gun ever, it is among the largest hand-held, single person (not crew served) weapons that had been in common use. If your looking for length, the Lhati L-39 is the longest single-person weapon in use with a military that has the possibility of being hand-held.
The Potato Gun
They used to be held in November or December.
A hand-held microphone is a microphone that you hold in your hand, such as you've seen being used in concerts, and most other public occasions.
Hand lens
Hand lens.
A tachometer measures RPMs, and a hand held tachometer is used to measure the speed of smaller things, like engine parts. A hand held tachometer is usually used to measure the RPMs in a car engine, but tachometers have also been used to measure the rate of blood flow in the body.
A magnifying glass is a hand-held instrument used to make an item look larger by magnifying its image when viewed through the lens.
Actually, it is the hand held basket used in jai alai.
A Metrologic barcode scanner is a hand held device with holographic technology used to scan the barcodes of items. The scanner can be securred in a static position or used remotely as a hand held device.
they used hand held lenses and later microscope.
The DC current used to operate a hand held massager should be safe for use for people with a pacemaker. It is always best though to check with your cardiologist and / or the manufacturer of your particular pacemaker.
The Saturn V used in the Apollo missions.