Schick Hydro 5 Sense Hydrate Men’s Razor Blade Refills, 4 Ct

4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5.

4 is the smallest square number > 1, the smallest semiprime and composite number, and the 3rd highly composite number.

The number 4 is considered unlucky in many East Asian cultures.

5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number.

Humans, and many other animals, have 5 digits on their limbs.

A blade is the sharp, cutting portion of a tool, weapon, or machine, specifically designed to puncture, chop, slice, or scrape surfaces or materials. Blades are typically made from materials that are harder than those they are intended to cut. This includes early examples made from flaked stones like flint or obsidian, evolving through the ages into metal forms like copper, bronze, and iron, and culminating in modern versions made from steel or ceramics. Serving as one of humanity's oldest tools, blades continue to have wide-ranging applications, including in combat, cooking, and various other everyday and specialized tasks.

Blades function by concentrating force at the cutting edge. Design variations, such as serrated edges found on bread knives and saws, serve to enhance this force concentration, adapting blades for specific functions and materials. Blades thus hold a significant place both historically and in contemporary society, reflecting an evolution in material technology and utility.

In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understood.

Hydro (from Ancient Greek: ὕδωρ, romanized: hýdōr, lit. 'water') may refer to:

A razor is a bladed tool primarily used in the removal of body hair through the act of shaving. Kinds of razors include straight razors, safety razors, disposable razors, and electric razors.

While the razor has been in existence since before the Bronze Age (the oldest razor-like object has been dated to 18,000 BC), the most common types of razors currently used are the safety razor and the electric razor.

S, or for lowercase, s, is the nineteenth letter of the Latin alphabet, used in the English alphabet, the alphabets of other western European languages and other latin alphabets worldwide. Its name in English is ess (pronounced ), plural esses.

Schick may refer to:

• Schick (razors), a brand of safety razors

A sense is a biological system used by an organism for sensation, the process of gathering information about the surroundings through the detection of stimuli. Although, in some cultures, five human senses were traditionally identified as such (namely sight, smell, touch, taste, and hearing), many more are now recognized. Senses used by non-human organisms are even greater in variety and number. During sensation, sense organs collect various stimuli (such as a sound or smell) for transduction, meaning transformation into a form that can be understood by the brain. Sensation and perception are fundamental to nearly every aspect of an organism's cognition, behavior and thought.

In organisms, a sensory organ consists of a group of interrelated sensory cells that respond to a specific type of physical stimulus. Via cranial and spinal nerves (nerves of the central and peripheral nervous systems that relay sensory information to and from the brain and body), the different types of sensory receptor cells (such as mechanoreceptors, photoreceptors, chemoreceptors, thermoreceptors) in sensory organs transduct sensory information from these organs towards the central nervous system, finally arriving at the sensory cortices in the brain, where sensory signals are processed and interpreted (perceived).

Sensory systems, or senses, are often divided into external (exteroception) and internal (interoception) sensory systems. Human external senses are based on the sensory organs of the eyes, ears, skin, nose, mouth and the vestibular system. Internal sensation detects stimuli from internal organs and tissues. Internal senses possessed by humans include spatial orientation, proprioception (body position) and nociception (pain). Further internal senses lead to signals such as hunger, thirst, suffocation, and nausea, or different involuntary behaviors, such as vomiting. Some animals are able to detect electrical and magnetic fields, air moisture, or polarized light, while others sense and perceive through alternative systems, such as echolocation. Sensory modalities or sub modalities are different ways sensory information is encoded or transduced. Multimodality integrates different senses into one unified perceptual experience. For example, information from one sense has the potential to influence how information from another is perceived. Sensation and perception are studied by a variety of related fields, most notably psychophysics, neurobiology, cognitive psychology, and cognitive science.