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
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.
They used to be held in November or December.
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.
Magnifying glass