4W 圆形 LED 灯泡 E14 透明，自然白

The end of the lamp that fits into the socket.

The description of the general appearance of a lamp/bulb consists of a letter(s) followed by a number. The letter indicates the shape of the bulb, and the number relates to the diameter of the bulb in millimetres. For example, a standard household bulb is the A60. The bulb is "A" shape, and the diameter would be 60 millimetres.

This voltage specification denotes the voltage level required for the LED bulb to operate correctly.

A rating, expressed in watts, indicates the rate at which a lamp consumes energy. Also known as wattage value.

A lumen measures the amount of visible light emitted by a source per unit of time. It indicates the brightness or illumination power of lamps and lighting systems.

An expression of the hue of the light emitted, measured in degrees Kelvin. Usually expressed by a four-digit number followed by (K), such as 2700K. High temperatures indicate white, "cooler" colours, while lower temperatures indicate yellower, "warmer" colours. Some typical Kelvin temperatures are 2700K (warm white) and 4000K (natural white).

The Colour Rendering Index is an international system that rates a lamp's ability to render objects colours. The higher the CRI (based upon a 0-100 scale), the richer and more accurately the colours appear. CRI differences among lamps are not usually visible unless the difference is more than 3-5 points.

Indicated whether a product can be dimmed in conjunction with a suitable dimmer control.

The wattage value of an incandescent lamp of similar brightness.

The surface finish of a bulb may affect the brightness of the emitted light.

Light bulb: a measure of a bulb's width taken at the widest point of the bulb. Fixtures: the measurement across the widest point of a circular fixture.

It is also referred to as "Maximum Overall Length" (MOL). For light bulbs, it measures the length from the top of the bulb to the bottom of the base or pins and is typically expressed in millimetres.

A measure of the average length of time between first use and the point when 50% of the lamps tested have stopped functioning, using an operated cycle of 3 hours on, 20 minutes off.

The width of a light beam is expressed in degrees.

The primary material used in this product.