If you're using a sleeve for self-pleasure, the last sensation you might want is cold. (If you'd wanted to take a cold shower you could have done that on your own.)
Engineers to the rescue: the Ninja Heat VibeSleeve is a hard-shelled cap with an enveloping, soft interior sleeve that both heats and vibrates. Our testers felt (a hem) that the heat was a nice change and much more arousing, while the vibration is specifically placed at the frenulum for maximum arousal. Operates more than 1hr at full speed. The hard shell makes it easier to hold, since you don't need to squeeze if you don't want to. Easy to clean with a splashable interior and vibrator is rechargeable for no battery fuss. Weather the cold by making your own heat.
Size: orafice is irregularly shapped and slightly stretchable with 1.25" x 2.5" deep. Case size 4.5" long x 2.5" wide.
Color: Black & red.
Material: Silicone interior
Batteries: None. USB charge cord included.
Care & Cleaning: Splashable, use non-moisturizing soap and warm water to clean; do not use silicone lubricant