[REAL Fully-Sealed Optical Projector with Cooling System] VIZONY RD830 is the first one REAL Fully-Sealed Dust-proof projector on the market, fully enclosed optical engine, active heat dissipation, no dust ingress, reducing black spots, noise and image quality loss, making it more durable compared with other traditional open optical projectors or semi enclosed optical projectors; Also backed by a 3-YEAR warranty, professional customer service and free tech support is available. [800 ANSI Full HD Native 1080P Projector 4K Support] VIZONY RD830 4K WiFi projector adopted independent R&D intelligent noise reduction tech, greatly improve the brightness up to 800ANSI, at least 95% higher resolution and clarity than other 1080p WiFi projectors, with clearer images and more vivid image quality; This home theater projector supports Ultra HD 4K Videos, H.265 30hz/MP4 format 4K video decoding, eliminate the anxiety of video stagnation, and bring you a true visual feast. [WiFi 6+5G/2.4G Dual Band WiFi & BT 5.2] VIZONY Bluetooth projector with WiFi 6 chip, 5G+2.4G dual-band WiFi, it can achieve a max rate of 9.6G bps and strengthen the anti-interference ability, the transmission rate is faster than other 5G WiFi projectors. Latest BT 5.2 allows it to be used as standalone Bluetooth audio, come with a 15W dual stereo speaker, it can provide crisp and loud tweeter and bass output without external speakers, also can connect a BT speaker to enjoy a theater sound. [Electric Focus+4P+4D Keystone Correction] VIZONY WiFi smartphone projector with Electric Focus, one-click remote control can easy obtaining clear image! Combined with 50 vertical/horizontal Keystone Correction, plus 4P, allow you can adjust the image vertically/horizontally manually, it overcomes the limitations of room angle in various ways, bringing flexibility to front/side/ceiling projection. 50%-100% zoom allows you to adjust the image to the correct size without moving it.