Borescope Cameras

Ralcam probes come in 3.9mm, 5.5mm, 6.2mm and 8.5mm. 6.2mm is the all-round standard with the brightest image. For diesel engine glow-plug and injector bores, choose 6.2mm or smaller; for gasoline car spark-plug holes an 8.5mm probe also fits. Use 3.9–5.5mm for the narrowest bores and 8.5mm when you want a larger, brighter view and the opening allows it. Measure your smallest access hole before ordering.

Rigid tubes hold a fixed shape and push straight into an opening — best for shallow, in-line inspections. Semi-rigid cables bend and hold the shape you give them, so you can route around obstacles and it stays put — ideal for engine bays. Flexible cables follow gravity and existing curves, best for drains and ducts. Ralcam offers all three across the 6.2mm and 8.5mm ranges.

Both types run on their own rechargeable battery, so neither one drains your phone — the real difference is the screen. Phone-connected scopes (F408A, F606A, H406A) are lighter and cheaper and use your phone's large, bright display, saving photos and video straight to your camera roll; charge them before use, like any cordless tool. Built-in-screen models keep your phone in your pocket, work where you'd rather not expose it, and start instantly. If you already carry your phone everywhere, phone-connected is the value pick.

Articulation means the camera tip bends on command, so you can look around corners instead of only straight ahead. 2-way models steer the tip in one plane (you rotate the probe body to reach any angle); 4-way models add a thumb joystick for full 360° control. It is what lets you inspect cylinder walls, valves and turbine internals.